WTF. Radeon 7600 and you're saying it can't handle AO???
AO has literally nothing to do with this. Unless 'disablign AO' also 'removes all your broken shaders that do something absurdly wrong'?
It will take litearlly 5 minutes of waiting while my machine grinds to a halt for me to get into the menu to be able to try this - that's how bad the current build is.