DC burning problems

[gibbon]

Im having a problem burning a few games and was wondering if anyone has any ideas. The games are gauntlet legends, urban choas and wsb2k and they all do the same thing.
After the initial dc boot up it just goes to the menu screen. The dc recognises the disc as a game cause I can select this in the menu but if i do same thing happens. Ive even tried converting them from a cdi to a nero image but still no joy. These are the only games Ive ever had a problem with

TIA