Since hotfix patch (Nov.8th), I was unable to play because my PC would freezes up soon as I start the match. Mechlab would work fine without a problem.
I have ATI Radeon HD 4870 X2 (note, this is a single card with two cores on it) with Catalyst 12.6. By default, I had Catalyst A.I. setting on standard. Disabling A.I. had fixed the issue I was having.
Hope this will help. I'm not sure if this could be related to Crossfire setup.
Edited by Nacon, 13 November 2012 - 07:35 PM.