i modded my saturn and days later went away and didn't touch it for 9 months. got back, everything worked as fine as the day i left it. are your discs recently burned? i've had dreamcast cd-r's go bad before
All my disks are 3-4 months old, except one which is only a few days old. I've never heard of CD-Rs going bad before, so I doubt all 20 or so of my games went bad.