I would take time to answer but I'm on my way home...

Obviously NOT true!  The additional information you've provided is excellent, thank you.  I just might ping you one evening to see if anything we've done corrects the issue for you, thank you.  In the future please feel free to contact me directly regarding any issues you might run into when using our web properties.

Well you certainly have my permission to leave early!

Of course, my permission doesn't count for squat!

Actually running with IG.com in the INet zone and Protected Mode on breaks a few other things as well. Logging in takes a second click on the Login link (click once, enter password, then click again before the user name shows up.) Logging in from the home page results in a blank page and requires navigating to the home page again (refresh isn't good enough) before the user name shows up.

I dl'd the 2008.2 release back in June when I built this computer and didn't have these problems. Perhaps a MS update to IE7?

I'm usually working late in the evening; let me know if you need any more info.

Just as a follow up, I moved *.infragistics.com to the Trusted Sites zone with Protected Mode Off and the download worked. (I should have tried this first.)

I'm assuming that the Infragistics web site is in your Trusted sites zone; try it in the Internet zone and see if it makes a difference.

With all the settings in IE7 on Vista it's a little tough to know how to answer the question "what level of security are you running" but, it's the Internet zone, Protected Mode is On, and Javascript is enabled.