HD7870 CrossfireX - black flashing artifacts if i alt tab

[Fox.SV]

Hi guys, i have a strange problem with ShootMania Storm and my HD7870 Crossfire. If I press ALT TAB when i am in game (also in menu) when i come back to the game i see many black artifacts flashing on the screen randomly. The problem disappears if I disable crossfire (from AMD profile cp)

It's not an harware problem, because i tested the crossfire setup also on many other games (ArmA 2, Arma 3, Quake, Far Cry and many Others)

Please help

[TMarc]

Something similar was reported not too long ago I think.
If you go first in window mode before doing ALT+TAB, does this happen still?