10.5 Server and 10.6 client sync issues

Basics:
Server
2x2.66 Ghz D-C Xeon based Xserve
10.5.8 Server
Services:
AFP
OD
DNS (though DNS resolution is provided by a Windows based server for the network, forward and reverse DNS works locally and across the network)
SMB
XRAID with about 3TB of storage for file sharing and hosting PHD

Client
Mix of 10.5.8 and 10.6.6 Mac Pros and MacBook Pros
Connected via Gigabit

Scenario:
The server has been is use as file server and PHD server since 2008. All clients were using 10.5 at rollout and set up to use PHD for user accounts. Workstation users work with Adobe (Illustrator, InDesign, Photoshop) based files that cannot not be worked on across the network due to Adobe recommendations. Laptops also use PHD because they are laptops.

Several exclusions have been set in the WGM: Mobility settings to prevent Microsoft User Data (using Exchange server) and other folders from syncing to the server. This set up has worked with no real issues since implementation, including user folders that have been successfully restored after disasters, etc.

*Enter 10.6:*
The first workstation with 10.6 pre installed arrived on site last summer, the user data was migrated after the PHD folder had been synced down from the server (to retrieve the data not synced to the server) by hand without replacing anything pushed down from the initial sync. At some point after this, the user began experiencing Home Sync Errors during background syncing. It involved a few different files, but the culprits were almost always one of 3 types of files:
- Suitcase based .fontvault
- Indesign (CS3, CS4, CS5) based .idlk (temp files associated with any open ID file)
- Skype based .pid and .db files

Various methods have been used to excluded these files and suppress errors with no luck. I have edited the Home Sync preference manifests in addition to the WGM: Mobility GUI based rules. No combination of terms for exclusion ("skip") or suppression will prevent these useless home sync errors from appearing on the workstation.

At first, I believed the problem to be isolated to the one user/workstation on 10.6 because none of the other clients had this problem. After the arrival of 3 more 10.6 based machines, we have now confirmed the issue affects everyone using 10.6 with the 10.5 server. This includes a Mac Pro that was upgraded to 10.6 from 10.5 (which had no errors previously) and a freshly created account. Open an ID document, launch Skype and forcing a Home Sync produces the same errors:
"There is a problem syncing the file "xxxx.xxx. A problem occurred. Please try again later. If this problem persists, contact your network administrator" There can be several error messages that must be clicked through one at a time for the user, very annoying to say the least.

The worst part is these are inconsequential files we'd prefer not to sync, but I cannot get the exclusion to take. I can confirmed the updated .plist file gets pushed down to /Library/Managed Preferences folder. I have tried removing both the user account from machine (logging in again to recreate the account locally) and the .Filesync folder from the user's account folder on the server if it existed. Looking in the verbose Filesync log on the client, I can see the affected files produce a 'Resource temporarily unavailable' error mentioning the affected files.

Additionally, opening the users's Mobile Account Preferences causes System Preferences to crash without exception. Users used to be able to enter this area to exclude files, etc.

Did something break in the way PHD file syncing handles 'in use' files like the one listed above? Anyone seen this or have some insight? I can provide more details if requested, but this message is getting too long as it is.

Thanks,
Shawn