Enhanced protection mode problem?

Hi guys,
Ok my problem is I upgraded CIS 5.5 to 5.8 when it was released. I enabled Enhanced protection mode and within a few minutes it froze my pc. If i tried to run an application or broswer or if i did nothing it would just freeze.Once its disabled my pc is fine. So I tried uninstalling and doing a fresh install, still the same so i left it off. Few days later i decided to install Avast av but kept comodo firewall. I re-enabled enhanced protection mode with Avast installed and its working fine. I tried installing Comodo av again and it froze again with enhanced mode enabled.
I have nothing else installed that would be conflicting with Comodo. I would like to keep enhanced mode enabled as im running Vista 64bit.
Anyway i just thought id post this and if anyone has any advice it be would great.

Please trying reinstalling it using the advice given in this post and let us know if you still have problems.

Your problem could be due to problems from a previous installation.