At the moment I am getting between 2 and 5 FPS. Specs are:

ATI Radeon 2900XT 512MB
2.4 Ghz Core 2 Duo
2GB RAM
Win 7 32 Bit

I played it this morning ( started the tutorial) and it was fine, after the space segment when you land again, it then got really terrible.

Any fixes for this?