Address bar on Popups won't go away

I have an INTRANET application running through an IFRAME on an HTA. Each user in the company installs the HTA on their client machine, and the HTA fills its IFRAME with the intranet app.

The problem is, since installing IE7 on client machines, any popup windows (via window.open) always show a grayed-out version of the address bar. We have the window.open set to "address=no" just like always, and, YES, we have set IE7's new zone settings to always allow popups without address bars in Intranet zone and all zones (out of frustration). If we launch the intranet app in a regular IE7 webbrowser, the popups do NOT show the address bar, just like we want. But once we browse to the same page through the HTA, it goes back to putting the grayed-out address bar on the popups. It is a trusted site! Why

As a note, we have the IFRAME's APPLICATION attribute set to yes.

Any ideas

Thanks