Window flashing every 3-10 seconds

[Grumpo]

Here i caught an in game flash or blinking :

one part (sometimes none) stays visible, everything else is white..

[BB_Saqui]

Yep did that too. Chrome and Opera seem to have the same response. Firefox doesnt even log in. Safari is lagging horribly.

If there are 5 more checks, please list them all in one go

The last thing to do is to try and uninstall and reinstall your Flash plugin, to make sure it isn't corrupted in any way.

[Grumpo]

Done that too. Twice now. No changes..