We have a pretty significant issue with our virtual copy of IE7. Users are unable to install ActiveX Objects. When they try, they get an information bar message stating the following...
"Your security settings do not allow websites to use ActiveX controls installed on your computer."
Of course, right away, this sounds like a security setting in IE...but I have everything set the way it should be. The really odd thing is that things work fine when I'm logged in as an admin. It's just under Power User profiles that it's not working.