Can't change Restistriced Sites under Internet Properties

I guess I have something being loaded that will not let me change
"Restricted Sites" under the Security Tab of Internet Properties. I can
not add or delete. I can go through the motions, but when the list
reappears, the same sites are listed. I don't think it is malicious
software doing it, because the sites are not useful sites.

BTW, I have tried deleting these domain entries in the resgistry, but of
course they reappeared.

I suspect it was some spy/adware software I once installed, but for what
ever reason, did not uninstall this *feature*. I am not one to try every
program on the face of the earth, so I would suspect it is something left
over from Norton's Antivirus, Zone Alarm, Spybot, Lavasoft's Adware, or
the two MS programs (Antispyware and Defender if my memory serves me
right) that is suppose to stop that spyware.

I know when I installed Norton's Internet Security 2007, it told me I had
to uninstall these things. I don't think I had any crashes during the
uninstalls.

Anyway, any ideas of what might be loading thses??

Thanks!

You know what to do: shdb at slip dot net