hi thanks for your tips i used the fomm toggle invalidation button and Fose is installed. I am currently using patch 1.6( i heard 1.7 was causing a lot of instability am i mistaken by that?) I searched for a while and tested some things - i think the crashes relate to my use of Alchemy. Ive got a x-fi soundcard and get terrible radio issues without alchemy - with alchemy the radis stutter is gone but the game will crash all 30 minutes. Is there any fix to this problem? I am running vista 64 bit.