Jet Grind Radio messing up...

I mount JGR, thing boots up, works fine.

See the Dreamcast swirl, that's a good sign. FPS is at a decent rate.

See the "we-do-not-condone-graffitti-please-don't-sue-us" disclaimer, and FPS is doing fine too.

See the "now loading" screen, and here is where the frames start to drop.

See the start screen, now this is where the FPS goes to the dumps and the sound goes along too. Chankast barely breaks the 13 fps mark, and the sound resembles a screaming cat. The situation is not improved even when I've tried Zwrite/Alpha Zwrite/Capcom Hack/some combination of the 3.

The game is on the Compatability List, and according to the comments it should work fine, but it hasn't (for me).

Any help at all?

Specs:
Pentium 4 2.6 Ghz
1.5 gigs of ram
ATI Radeon 9200
Windows XP

The menu isn't the only thinking messing up; it's the entire game. You try playing the tutorial and you can barely move. Same thing with the regular game. Choppy sound and slow graphics.

I'm also getting this weird invisibility thing going on here where you can see right through the guy every now and then i.e. you're grinding on a rail and you can see the rail right through him. Sometimes the guy doesn't go invisible but instead turns black.

Bad rip?