Problem in System Preferences/Network

I have an odd problem in my system preferences/network. When I even tryo to look at the settings, basically immediately after I click on Network, the usual panel comes up then a message pops down "Your Network settings have been changed by another application." When I click OK, it comes down again; it won't go away, just keeps popping back down. I can't close System preferences, either; have to do a force quit. Have any of you come across this and what was the fix? I realize a straight troubleshoot would entail looking into a lot of settings, etc. I hoped it had been done before so I don't have to re-invent the wheel or do a re-install of the OS.

I'm running 10.4.11 , Firefox (though this does it with Safari, too), and Intego virusbarrier and net barrier (possible culprit?). Happens on both iBook G4 and iMac G5.

Thanks,

There are numerous posts about this issue on this and other Mac forums, eg. http://www.mac-forums.com/forums/os...-your-network-settings-have-been-changed.html.

Thanks. I did a search first but did not formulate the query correctly. Just use the error message as the search term - duh. Somebody must have checked my own "system preferences" dumb box.