I see you have CS 5.5. What's the OS?
It won't hurt to have Service Pack 1 if don't have it already.
You may need to uninstall AE and other CS5 applications, run the Adobe Cleaner application (downloadable from Adobe), then reinstall with the antivirus/firewall software TURNED OFF. It can inhibit proper installation.
Before jumping into this somewhat drastic measure, I would wait for other opinions.
I'll hold fire to see if further opinion come in but otherwise i'll give that a go.
I used the Cleaner application and re-installed without my Firewall and it seems to have done the trick.
Thanks again, Dave.