PS2 backups and Modchips - how stable?

[deet]

I'm still having trouble burning ps2 backup images. I've burned hundred of games for pc using cdrwin, but can't get it to work on PS2. So far the ones I've gotten to work crash quite often during the game or have extremely long load times and sometimes the same disc doesn't work at all. Just wondering if this is normal, or is it supposed to work perfectly everytime you boot up a backup using the R1 + O method?