I don't remember having any major issues installing/playing GTA SA, occasionally a rare crash when loading a save or stopping by the ammo place. The only Direct3D tweak I have in my user.reg is "PixelShaderMode"="disabled", which is probably the same thing jorl17 is talking about. I suggest you start over with a new WINEPREFIX (export WINEPREFIX=/new/wine/dir ; wine /cdrom/setup.exe ; wine /new/wine/dir/path/to/gta_sa.exe or mv ~/.wine ~/.wine.old), disable shaders with winecfg, install the game, then try again. Whenever things go horribly wrong, I always start over with a new WINEPREFIX and I always install my games in separate prefixes so problems in one won't affect the other. The GeForce 4 MX is probably a bit low (says a GeForce 6 is recommended), but I'd expect the 7300 to handle the game alright. It plays fine on my GTX260, but that's quite a step up from the 7300..
