IOS Reload Block
This is a D2X cIOS setting to prevent the current game from switching to another IOS which would cause us to lose connection with a USB HDD or SD card. This is not available via Waninkoko's cIOS and may not be available via Hermes cIOS (I see some sort of patch in USBLGX for Hermes, maybe the Rodries mod).
Here is an explanation taken from GBATemp user PPSainity (https://gbatemp.net/threads/ios-reload.297230/post-3713863):
When the Wii Loads a title/dol/game it loads a requested IOS that has all the features used by the title. Normal IOS from Nintendo are not capable of playing backups or playing games off a USB drive. So we use loaders which can load a cIOS (customized IOS) of our choosing instead of the IOS normally requested by the title. When we load the cIOS, it will be set to do certain things like use the USB Drive instead of the Wii's DVD drive. Problem is some games have more than one dol that are run. Often the first dol that is run is just a small menu program that then loads the appropriate game dol depending on what is chosen. When the new dol is loaded, it requests a certain IOS to be loaded, and we loose all the advantages of the previously loaded cIOS as it has been replaced. By blocking the cIOS from being reloaded, we keep it from being replaced and we keep it from loosing certain settings like when it is set to use the USB Drive instead of the Wii's DVD drive.
As of d2x v8 IOS reload block is now enabled by default. Wiiflow and USBLGX contain d2x commands to enable it, must be in case you are using an older d2x version.