Vista - AxIS Not working?

I'm working on setting up Group Policies for our Windows Vista deployment.

One of the technologies that really excites us is the ActiveX Installer
Service. We have a couple of applications that rely on ActiveX and it's been
prevening us from removing admin rights from the desktop in XPSP2.

So I set up a Computer GPO that specifies under ActiveX Installer Service:

http://et - 2,2,2,0
https://2k3-tm8 - 2,2,2,0

I then restarted the Vista workstation, made sure that the computer received
the policy with RSoP, logged in as a standard user, and tried to do the
ActiveX install. I still get the elevation prompt, and an error is logged:

Source: AxInstallService
EventID: 4097

Attempt to install control http://et:6973/newlook7/newlook.cab failed. The
host URL http://et is not in policy

I've tried a bunch of variants of the URL in the GPO, including
http://et:6973
http://et/
http://et:6973/

This also does not work with the 2K3-TM8 server either. I get the same
error, and I've tried an equal number of variants in Group Policy.

Am I missing some big step here?