Folder properties and sharing inaccessible - XP Pro, SP2

I am running XP Pro on an Athlon 1900 computer, just updated to SP2 with no
problems except this one as far as I can tell. I am also running Norton
Antivirus, Norton Internet Security, Norton Personal Firewall.

I have seen some earlier posts re this folder properties problem, and tried
Kelly's Tweaks, to no avail.

Since installing SP2, right clicking on a folder and then mousing to
"Sharing and security" or "Properties" does not do anything in the pop-up
window (all other actions like "Explore" etc. work fine).

This is a major problem for me as I need to share some folders on my home
business network between computers.

Has anyone found a solution yet?

Thanks

Alan