PS3 Guitar Hero Controller Issues

I discovered this the hard way last night, just so no one else wastes their money:

 
PS2 controllers do not work with Guitar Hero III for PS3, even with a controller adapter. I was super sad because I wanted to play Co-op career. Lame sauce.
Trisha had a really epic biography, but made us take it down. Something to do with government conspiracies, Cthulu, and being the "Chosen One" or something. You can follow her on Twitter @TrishaDuerr.