Punkbuster...
I used to have the same problem with GameGuard. After some research, I found out that video switching on my laptop (from integrated Intel HD to the Nvidia 310M) caused it to raise a flag with GameGuard and Punkbuster. That's just in my case. So if you're in a similar situation, try to make sure it's running only on the integrated graphics. You can set it through the Nvidia Control Panel.
If it's something else, then I don't know. Hope that helps.
Oh, and a recent GameGuard update allows the graphics switching with no problems. (Part of why I play lots of AVA and Genesis AD now. Yay!)






