Actually, I just found a work-around:
1 - Make sure Ad Muncher is enabled & running
2 - Open Vista's IE7 with Protected Mode off and visit a site (i.e. google or whatever)
3 - Change IE's Security option to enable Protected Mode (Tools Internet Options Security)
4 - IE7 will want to open a new window to reload the page in Protected Mode - let it go ahead and close the first window And that's it - seems to work A-OK for me. Even if I close IE7 now, and later reopen it, Ad Muncher will still work with IE7 in Protected Mode and with UAC at default settings.
One other thing, though:
Don't forget to reset the Protected Mode to off before restart or shut down, otherwise you need to reset IE7 to Protected Mode off next time you fire up Vista and want to go online, and then go through the above 1-4 steps ...
One more thing I noticed: The very first time you switch from Unprotected to Protected Mode, you need to re-enter all your passwords for any password protected sites you are visiting (i.e. this great forum, hotmail et al).
Though luckily this you only have to do ONCE!
Forum