SYNC ISSUES: Microsoft Office Docs/Portable Home Directories.

Greetings, all. Running a main AFP/Open Directory/Portable Home Directory server on Mac OS X Server 10.5.8. Lately, for some reason - clients on Mac OS X 10.6.3+ are seeing conflicts when background syncs occur with Microsoft Office documents. More specifically - if they have a open Microsoft Office document they are working on, the Finder on the client kicks up a sync error dialog box. Needless to say - that's quite annoying for the users. Has anyone else seen this behavior at all? Many thanks in advance, [b]