Avast, IE9 x64 and Google Chrome Frame

[Nesivos]

I decided to install the IE plugin Google Chrome Frame

https://secure.wikimedia.org/wikipedia/en/wiki/Google_Chrome_Frame

to IE9 x64 on both my desktops.

The installations went smoothly however AIS did not handle the two installations similarly.

On one of my W7 SP1 x64 computers AIS popped up during the install and with the message "Allow and Add To Trusted Programs"

On the other one of my W7 SP1 x64 computers AIS did not pop up at all.

Anyone have any idea of what is going on here?

Please don't suggest uninstalling and reinstalling without an explanation of why this is happening.  Thanks

I am looking for a reason for the difference.  Only once that is identified will I consider a possible solution.   By the way IMF popped up twice on both installs.  The first time asking for permission to run the installer and the second time asking for permission to install the actual plugin.

[mikaelrask]

i think that avast does not have that program in there whitelist so it should only to trust and add to whitelist sens it comes from a trustworthy company (Google).