I am suffering from exactly the same issue.
Seems fairly rare, not a huge amount of threads of the net about it so i guess i ought bump this.
Only an issue in editor and multilayer but since I would like to play dayZ, this is a serious problem.
I have tried a clean install of Arma and Arma OA, tried them separately and before and after patches, I even did a format and a fresh windows 7 install and this issue is still plaguing me.
Running windows 7 64bit.
AMD 12.4 graphics drivers.
Any suggestions would be most appreciated, I am at the end of my tether, I need to get on dayZ.
