Cary,
If memory serves, you can turn DEP off or, if you like, add custom app entries so DEP 'allows' execution.
Check into that when you get a moment.
Next, and extreme, you might consider whacking IE8 and rolling back to IE7. We run enterprise-class software
at work...the vendor of that software indicated NO compatibility with IE8 until mid 2011 so we told our end-user
community NOT to upgrade. Well, they did
So our only solution was to remove IE8 completely (which included douching the registry) and re-installing IE7.
This got rid of the plug-ins and extensions as well; a good thing in our case.
I believe MS still makes the IE7 installer available to download. It's small but when it kicks off, it starts downloading
the full installation media.
Just an idea...