SharePoint and Active Directory Sync Issues

In our environment we have a SharePoint server (SharePoint 2007) that synchronizes with the Active Directory (Windows Server 2003) nightly. Unfortunately, while attempting to set up alerts for one user (and strangely this sole user), we ran into a bit of a problem by way of email addresses. This user’s email is correct in the Active Directory, but incorrect in SharePoint. Stranger still is that it is only incorrect in the alerts section; in all other information listings it is correct.

We have tried updating the Active Directory profile with the correct email several times, manually editing SharePoint (which has yielded no results and has proven ridiculously difficult), and forcing SharePoint to manually synchronize with the Active Directory, all to no avail.

Both of these servers are completely updated and neither alone have problems. Any ideas (short of deleting this user’s profile completely and recreating it) as to why this is happening and how to fix it?