stealth mode?

flickering issue could be gpu or the game problem but do u face any flickering issue from other games like cod mw2, bfbc2?

SC2 does support Crossfire. It could be ur driver issue, but would u mind to tell us ur catalyst version?

If all the driver are up to date
try reinstall the game and patch them with the latest patch.
maybe that will help.

They patch up the crossfire/SLi for sc2 retails. That leaves ur driver is at fault.

Weird, when I play SC2 in ultra setting, 1v1 A.I, i get 50-60 fps constantly.
But when I play 1v1 on battlenet, the FPS drops down to 30-40fps = =
what's the problem

EDIT:

notice a strange slow down on Bnet gameplay..

Spec:
Win7 Ultimate 64bit
i7 740QM (2.9ghz)
8GB RAM
5850m (Overclocked from 625mhz to 790mhz)
128GB SSD

When I play 1v1 with A.I, I get 50-60 FPS constantly on Ultra.
But when I play 1v1 on Bnet, on the same map, I gets only 30-40fps :/
I mean, It's 55+fps at the beginning when I play with A.I, is there any reason I can only get 30-40+ FPS on bnet, under same settings?

huhu any of your guys have problem with black screen at login using window 7?
anyway to solve?

im using M17x R2
5870 x2

There is no stealth mode.
There is only a "make my laptop useless please" button.