If it only happens after running the Wii for a long time, it sounds like this could be general hardware failure than something RetroArch itself is doing.@libretroretroarch
Since my first post I wanted to report a bug that is very difficult to tell when it occurs. I couldn't make it happen intentionally so I just skipped any mention of it. It was there on 0.9.8, 0.9.8.1 and now on 0.9.8.2.
It happened again just a few minutes ago...
I turned on the wii, ran retroarch, used the snes9x core to load two games. I let each run in demo mode for a couple of hours, I didn't play at all. Then I wanted to play a game in FBA. I switched the core, went to change resolution from 640x576i to 320x240. The moment the resolution mode went below 640x448i the screen got garbled and it could only be fixed by selecting 640x448i or above.
From then on, the emulator became very slow. Exited the emulator to the homebrew channel and the homebrew channel was also slow. Exited the homebrew channel to the wii menu and the wii menu was slow. The only solution was to shutdown wii and turn it on again. Then everything worked as usual.
It has happened before with different cores so it can't be core related. I've tried in the past to repeat the error but I couldn't. I'll try again but the only thing that I didn't try in the past was to let a core play for hours before switching cores and messing with the resolution.
Now that I finished writing this, I wonder if I should post it ... oh well ...
EDIT: Do you have a launch Wii? I know some of the earlier ones had issues where the graphics chip ran too hot.