Vista minimizing my active window without permission

Hello all,
My issue has to do with Vista minimizing my active window. I’ve had this computer for about 4 month and it never has done this before.
It started last week, while playing WoW it would just minimize down to the task bar. I then click on it to maximize it so I can start playing again. I haven’t download anything other than a few window updates in this time frame.
It seems to be happening randomly sometimes it will do it couple of times in a row and other times it will happen once during the night or not at all. Sometimes I’m casting a spell or moving and it happens and sometime I’m not moving and not even touching the keyboard or mouse and it happens. The only time I’m on the computer is to play the game or email so I can’t tell you if it happens with any other application. Anything you can tell to help correct this issue?
Thank you

Nothing happens after the active window minimizes (e.g. a tooltip balloon from the system tray)? Does this happen only with WoW, or any window? (Also non-fullscreen windows?)

I would check what programs/processes are running while this is happening (in task manager) and try to eliminate any one that may cause it. Also, I would look in event viewer to see if anything there might be correlated with the timing of the minimize. (Post screenshots if you want another pair of eyes to look over these)

I'm not sure what are the odds that this is related, but I would try running a bit without Aero and see if it still happens (if Aero is on while this is happening).

I believe I found the cause. A couple of weeks ago turned on Gamer mode on my anti-virus BitDefender. Well last night I was downloading a patch from WoW and BitDefender kept stopping the download. It believed one of the files was a virus. After confirm everything was okay with the download I turn off BitDefender....finish downloading the patch turn the anti-virus back on and starting playing the game. It never minimize in about 2.5 hours of play time. This morning I was about to log in again and I notice Gamer mode was off so I turned it back on....logged in and after about 15 min the active window minimized.
I still don't know why but I believe I know the who part. I'll test it out more this evening.

I have Aero turn off and I've turned off most unnecessary processes per Black Viper's website ( I think thats the name). I'll look in the event view but I might have turned that off too, not sure.

Thanks for the help so far.