Windows Problems?

I always run CoH in full screen mode. But I am usually in between missions or sometimes in the middle of them(lol!) alt-tabbing out of CoH to change a song on youtube, or check my email etc. Sometimes, but not always, when I alt-tab back into CoH I am seeing the CoH screen, but when I go to click a power, it's like I am on the window below it? I really hate going to click cinders, and next thing I know I'm bumped out of coh and it's clicking on an IE link on youtube or something.

So why am I seeing the CoH window, but my clicks are sometimes hitting pages on the desktop? Can I fix this? Also, related....sometimes to alt-tab out of coh takes me two attempts. the first alt-tab basically brings me back to coh. Doing it again actually brings me to my other open window.

????