diff --git a/ChangeLog b/ChangeLog
index 9cd354cef..ecd2fe04c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,12 @@
 2005-03-03  Mike Kestner  <mkestner@novell.com>
 
 	* gdk/Gdk.metadata : remove unnecessary null_ok rules.
-	* generator/Ctor.cs : remove NullOk check.
-	* gnome/Gnome.metadata : remove unnecessary null_ok rules.
+	* generator/Ctor.cs : don't add null params to CreateNativeObject call
+	for InterfaceGen or OpaqueGen in addition to ObjectGen.
+	* generator/Field.cs : simplify Object/Opaque gen.
+	* generator/Method.cs : remove OpaqueGen special casing.
+	* generator/OpaqueGen.cs : make FromNative null_ok robust.
+	* generator/Signal.cs : remove arg marshaling ClassBase special case.
 	* gtk/Gtk.metadata : remove unnecessary null_ok rules.
 
 2005-03-03  Mike Kestner  <mkestner@novell.com>
diff --git a/gdk/Gdk.metadata b/gdk/Gdk.metadata
index 3cc6fa9d6..364afc800 100644
--- a/gdk/Gdk.metadata
+++ b/gdk/Gdk.metadata
@@ -25,7 +25,6 @@
   <attr path="/api/namespace/class[@cname='GdkGlobal']/method[@name='StringToCompoundTextForDisplay']" name="hidden">1</attr>
   <attr path="/api/namespace/class[@cname='GdkPango_']" name="name">PangoHelper</attr>
   <attr path="/api/namespace/class[@cname='GdkPixbuf_']" name="hidden">1</attr>
-  <attr path="/api/namespace/class[@cname='GdkPointer_']/method[@name='Grab']/*/*[@name='cursor']" name="null_ok">1</attr>
   <attr path="/api/namespace/class[@cname='GdkProperty_']/method[@name='Get']/*/*[@name='actual_property_type']" name="pass_as">out</attr>
   <attr path="/api/namespace/class[@cname='GdkProperty_']/method[@name='Get']/*/*[@name='data']" name="pass_as">out</attr>
   <attr path="/api/namespace/class[@cname='GdkProperty_']/method[@name='Get']/*/*[@name='data']" name="array">1</attr>
@@ -116,7 +115,6 @@
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='GetPointer']/*/*[@type='GdkModifierType*']" name="pass_as">out</attr>
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='GetToplevels']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='PeekChildren']" name="hidden">1</attr>
-  <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='SetCursor']/parameters/parameter[@name='cursor']" name="null_ok">1</attr>
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='SetIconList']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@name='GetUserData']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GdkWindow']/method[@cname='gdk_window_set_user_data']" name="hidden">1</attr>
diff --git a/generator/Ctor.cs b/generator/Ctor.cs
index 8e234e23e..159424f4d 100644
--- a/generator/Ctor.cs
+++ b/generator/Ctor.cs
@@ -124,7 +124,7 @@ namespace GtkSharp.Generation {
 							for (int i = 0; i < names.Count; i++) {
 								Parameter p = Parameters [i];
 								string indent = "\t\t\t\t";
-								if (p.Generatable is ObjectGen) {
+								if (p.Generatable is ClassBase && !(p.Generatable is StructBase)) {
 									sw.WriteLine (indent + "if (" + p.Name + " != null) {");
 									indent += "\t";
 								}
@@ -136,7 +136,7 @@ namespace GtkSharp.Generation {
 								else
 									sw.WriteLine ("new GLib.Value (" + values[i] + "));");
 
-								if (p.Generatable is ObjectGen)
+								if (p.Generatable is ClassBase && !(p.Generatable is StructBase))
 									sw.WriteLine ("\t\t\t\t}");
 							}
 
diff --git a/generator/Field.cs b/generator/Field.cs
index 1b41e576c..d8b068bde 100644
--- a/generator/Field.cs
+++ b/generator/Field.cs
@@ -197,10 +197,7 @@ namespace GtkSharp.Generation {
 				if (Access != "private") {
 					sw.WriteLine ("\t\t" + Access + " " + wrapped + " " + wrapped_name + " {");
 					sw.WriteLine ("\t\t\tget { ");
-					sw.WriteLine ("\t\t\t\t" + wrapped + " ret = " + table.FromNativeReturn(CType, Name) + ";");
-					if (table.IsOpaque (CType))
-						sw.WriteLine ("\t\t\t\tif (ret == null) ret = new " + wrapped + "(" + Name + ");");
-					sw.WriteLine ("\t\t\t\treturn ret;");
+					sw.WriteLine ("\t\t\t\treturn " + table.FromNativeReturn(CType, Name) + ";");
 					sw.WriteLine ("\t\t\t}");
 
 					sw.WriteLine ("\t\t\tset { " + Name + " = " + table.CallByName (CType, "value") + "; }");
diff --git a/generator/Method.cs b/generator/Method.cs
index ef0cd1e4a..1c38e3cea 100644
--- a/generator/Method.cs
+++ b/generator/Method.cs
@@ -327,19 +327,14 @@ namespace GtkSharp.Generation {
 			sw.Write(indent + "\t\t\t");
 			if (retval.MarshalType == "void") {
 				sw.WriteLine(CName + call + ";");
-			} else if (ret_igen is OpaqueGen) {
-				sw.WriteLine(retval.MarshalType + " raw_ret = " + CName + call + ";");
-				sw.WriteLine(indent +"\t\t\t" + retval.CSType + " ret;");
-				sw.WriteLine(indent + "\t\t\tif (raw_ret == IntPtr.Zero)");
-				sw.WriteLine(indent + "\t\t\t\tret = null;");
-				sw.WriteLine(indent + "\t\t\telse");
-				sw.WriteLine(indent +"\t\t\t\tret = " + table.FromNativeReturn(retval.CType, "raw_ret" + (retval.Owned ? ", true" : "")) + ";");
 			} else {
 				sw.WriteLine(retval.MarshalType + " raw_ret = " + CName + call + ";");
 				sw.Write(indent + "\t\t\t");
 				string raw_parms = "raw_ret";
 				if (retval.ElementType != String.Empty)
 					raw_parms += ", typeof (" + retval.ElementType + ")";
+				else if (retval.Owned)
+					raw_parms += ", true";
 				sw.WriteLine(retval.CSType + " ret = " + table.FromNativeReturn(retval.CType, raw_parms) + ";");
 			}
 
diff --git a/generator/OpaqueGen.cs b/generator/OpaqueGen.cs
index 86027cd52..f6a871436 100644
--- a/generator/OpaqueGen.cs
+++ b/generator/OpaqueGen.cs
@@ -32,7 +32,7 @@ namespace GtkSharp.Generation {
 	
 		public override string FromNative(string var)
 		{
-			return "new " + QualifiedName + "(" + var + ")";
+			return var + " == IntPtr.Zero ? null : new " + QualifiedName + "(" + var + ")";
 		}
 
 		private bool DisableRawCtor {
diff --git a/generator/Signal.cs b/generator/Signal.cs
index 4e4676ad8..183ffbc05 100644
--- a/generator/Signal.cs
+++ b/generator/Signal.cs
@@ -209,7 +209,7 @@ namespace GtkSharp.Generation {
 				IGeneratable igen = p.Generatable;
 				if (p.PassAs == "out")
 					finish += "\t\t\targ" + idx + " = " + igen.ToNativeReturn ("((" + p.CSType + ")args.Args[" + (idx - 1) + "])") + ";\n";
-				else if ((igen is ClassBase && !(igen is StructBase)) || igen is ManualGen) {
+				else if (igen is ManualGen) {
 					sw.WriteLine("\t\t\tif (arg{0} == IntPtr.Zero)", idx);
 					sw.WriteLine("\t\t\t\targs.Args[{0}] = null;", idx - 1);
 					sw.WriteLine("\t\t\telse {");
diff --git a/gtk/Gtk.metadata b/gtk/Gtk.metadata
index f1a02cfaf..38e6d12b5 100644
--- a/gtk/Gtk.metadata
+++ b/gtk/Gtk.metadata
@@ -335,7 +335,6 @@
   <attr path="/api/namespace/object[@cname='GtkToolbar']/method[@name='PrependElement']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkToolbar']/method[@name='PrependItem']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkToolItem']/signal[@name='SetTooltip']" name="name">TooltipSet</attr>
-  <attr path="/api/namespace/object[@cname='GtkTreeModelFilter']/constructor[@cname='gtk_tree_model_filter_new']/*/*[@type='GtkTreePath*']" name="null_ok">1</attr> 
   <attr path="/api/namespace/object[@cname='GtkTreeModelFilter']/method[@name='ConvertIterToChildIter']/*/*[@name='child_iter']" name="pass_as">out</attr>
   <attr path="/api/namespace/object[@cname='GtkTreeModelFilter']/method[@name='ConvertChildIterToIter']/*/*[@name='filter_iter']" name="pass_as">out</attr>
   <attr path="/api/namespace/object[@cname='GtkTreeModelSort']/constructor[@cname='gtk_tree_model_sort_new_with_model']/*/*[@name='child_model']" name="property_name">model</attr>
@@ -378,7 +377,6 @@
   <attr path="/api/namespace/object[@cname='GtkTreeView']/method[@name='InsertColumnWithDataFunc']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkTreeView']/method[@name='RowActivated']" name="name">ActivateRow</attr>
   <attr path="/api/namespace/object[@cname='GtkTreeView']/method[@name='RowExpanded']" name="name">GetRowExpanded</attr>
-  <attr path="/api/namespace/object[@cname='GtkTreeView']/method[@name='ScrollToCell']/*/*[@type='GtkTreePath*']" name="null_ok">1</attr>
   <attr path="/api/namespace/object[@cname='GtkTreeView']/signal[@name='SetScrollAdjustments']" name="name">ScrollAdjustmentsSet</attr>
   <attr path="/api/namespace/object[@cname='GtkUIManager']/constructor[@cname='gtk_ui_manager_new_merge_id']" name="hidden">1</attr>
    <attr path="/api/namespace/object[@cname='GtkUIManager']/method[@cname='gtk_ui_manager_get_action_groups']" name="hidden">1</attr>
@@ -407,7 +405,6 @@
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='Path']/*/*[@type='gchar**']" name="pass_as">out</attr>
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='Ref']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='SetEvents']/*/*[@type='gint']" name="type">GdkEventMask</attr>
-  <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='ModifyFont']/parameters/parameter[@type='PangoFontDescription*']" name="null_ok">1</attr>
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='Set']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='SetState']" name="hidden">1</attr>
   <attr path="/api/namespace/object[@cname='GtkWidget']/method[@name='SizeRequest']/*/*[@name='requisition']" name="pass_as">out</attr>