Have a client that gets an error message when starting Outlook 2003 from the Office/Educational package. Says that the "SBCMSYNC.DLL" is not a valid Office Add-in. Once she clicks "OK" the message goes away and she merrily goes about her work with no ill-effects.
I've done the Google search (MS KB235009) and looked in Outlook\Tools\Options\Other\Advanced Options\Add-in Manager and to uncheck the 'Outlook Sync', which isn't there. Also done a search for the Extend.dat file with no luck. Done the registry search in the HKCU\Software\Microsoft\Office\Outlook\Addins\Sbcm*.*, which isn't there also. Those are the MS fixes.
Uninstalled/reinstalled with no change. I believe I saw that Norton's (once again) had an issue but the link to it's "fix" was dead.