Any other with this problem?

[Kankkis]

You got 5970 too, something problem with crossfire maybe then, because if you use pseudo you have allways crossfire disabled and no this problem.
I dont get so good performance with pseudo because i cannot use vsync(terrible tearing without) and crossfire is disabled.

Really annoying problem, if i want smooth flight whole time i must keep myself in same mission all the time, because mission changes loss my good performance. I got this problem before latest beta too, it's not beta problem.