Same happens to me, when I alt-tab out CA still is open, but it won't let me go in the game anymore. I'll try using the flag button to alt-tab, ill report back laterz.
Edit: Flag button still won't work, Help?
Your hacks may be patched, if so get a PUB somewhere else on MPGH that's trusted and test it there.
You can use your Alt+Tab trick still, if it doesn't work:
If your hacks are good, then try using the Windows Button
If not, you can open the task manager using:
another way to open the task manager is:
If none of those are what you needed help on, then i'm sorry
if it did, a THANKS under my post would put a smile on my face