I'd like to share this information with others so you can spare yourself some hassle.
There are some video cards that won't work reliably with some dotclock values. While this is a minor issue with Soft15KHz and PowerStrip (as you can set your modelines avoiding the offending dotclock values), it's a big problem with Groovy Mame, because, even if you tweak the problematic modelines, Groovy Mame has the ability to alter the modelines present in the system to best suit any game it runs. Every now and then, it will choose a dotclock value that doesn't work, and you'll be angry.
I had this problem with the first 2 cards I bought, then the 3rd one worked perfectly. The 2 troublesome cards are:
- GeCube Radeon 9200 256 Mb AGP (GC-R9200-D3)
- GeCube Radeon 9200SE 128 Mb AGP (R9200L/SE)