Well I know this isn't helping but I'm still having the slowdown in loading screens, running the original games off disk seem to work fine though so it can't be my Gamecube mode is broken, something in DML is because it used to work normal before, I'm still in need of help for the slow loading times!
Have you used Panasonic SDFormatter to format your SD card?
Panasonic SDFformatter? no I just formatted it on Windows, does it matter?