I have exactly the same problem. I have alighted this strange bug in IE7 Beta 3 with this standalone loader just now. I can't avoid this even if popup filter is disabled too. I have just updated to IE7RC1 in hope this is already fixed, but it's not. I've used "Internet Explorer 7.0 RC1 Standalone Installer".

The main question is this bug related to standalone installer or IE7 itself?