Werid Self-boot problem

[lettuce]

Hi, im new to the forums, so sorry if this is a really stupid question, im learning about the self booting progs etc, anyway...

I have made 99% of my DC games self-booting, but am having a few problems making, Gauntlet Legends, Ferrari challenge, and Virtua cop, self-booting. For Gauntlet and Virtua Cop, it loads up to the Sega logo, but the goes back to the controller & memory card screen, i have also try gauntlet without making it self booting and using the boot cd and it does the same thing!!! Ferrari challenge goes past the Sega logo, and says loading on the screen, and then goes back to the Controller & Memory card screen!! Does anybody know why this is happening and what i can do to sort it out??? Thanks in advance if anybody can help!!