Just wanted to say that I concern with another post in this thread. I was having issues with very long wait times on the madsheeps sd card making. I used GDMENU Card Manager and just put in my existing SD card created with madsheep. I clicked save. Then I went and opened MAdsheep and using the same SD card doing nothing different clicked save......I now have instant load times. No idea why that worked but I read someone else in here saying they just saved on this and it fixed the issue.
When I just tried saving with this GDMENU the sd card would not boot in the dreamcast, so I just re-saved with madsheep and its instant now. No idea why just adding my 0.02