CO minimizes itself randomly while playing (MP&SP)

[SasCologne 1]

Hello, If I play any mission or mod or even vanilla Arma 2 Combined Operations, the game freezes and then minimizes itself. I can still see my mouse and hear all sounds but can't see anything else. To get back into the game, I have to press ESC -> Alt + Enter -> Alt + Enter.

This happens in Multi- and Singleplayer but it happens more if the server has more people on it or there are more people around me. (Example: Coop with 4 people: it sometimes doesn't happen more than once an hour; Wasteland with 60 people on server around a base: Every few seconds).

I've searched a lot via google and haven't found any solution for this problem. Reinstalling the game didn't help either. Apparently it is some kind of issue with Nvidia GPUs but I could not find a fix and most posts about that problem were a few years old.

My system: AMD Phenom II X4 945 Nvidia GTX 295 Windows 7 Home Premium 64 Bit 8 GB of DDR3 RAM

I can post more details if that's helpful.

I'm using Arma 2 Free in combination with Operation Arrowhead. I got the latest beta patch installed. I'm using the latest GPU driver (310.70)

I hope you can help me out :) I can provide further information such as a dxdiag or whatever if it's required.

[theobutters 1]

When your game closes does an error screen pop up?or a little bubble in the bottom right?mine minimizes when my antivirus tells me to update and stuff like that.

[gunso 10]

Can you confirm if only arma or all game/apps behaves like this, because there is a win7 issue called losing focus. I got it a while ago, a real pain to troubleshoot. It's like an automatic alt+tab that happened randomly.

[SasCologne 1]

Sometimes a little error bubble pops up saying that the nvidia driver version <xyz> has crashed. Doesn't happen everytime though.

I haven't had something like this in any other game. Only happens in arma.

Also it's not like a real alt+tab (which I can do manually and does not crash the game). The game freezes for a random amount of seconds (~1-5s) and then goes into that transparent, "only-the-mouse-is-visible", minimized state.

When I try to tab back in using ESC->Alt+Enter->Alt+Enter the screen stays black for a little while and shows the "Receiving..." message.

More information:

Video settings: http://imgur.com/0O123 (I have played around with most of the settings, except for ATOC, PPA, HDR, Vsync, AspectRatio. Visibility is on 10000 right now but if I play SP missions, I usually set it around 2000-5000)

I have also edited the Nvidia Control Panel and Arma config files like this: http://pastebin.com/CGTr3kii The bug happened before I did that anyways.