Well, you could never actually sync them, but you can disable the message!
Hmm.. there was an ExclusionErrorSuppressionList in XP.. not sure if it applies, but check here: http://support.microsoft.com/kb/811660
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\NetCache\ExclusionErrorSuppressionList]
"\\\\*\\*\\*\\*.PST"=dword:00000000
"\\\\*\\*\\*\\*.SLM"=dword:00000000
"\\\\*\\*\\*\\*.LDB"=dword:00000000
"\\\\*\\*\\*\\*.MD*"=dword:00000000
"\\\\*\\*\\*\\*.DB*"=dword:00000000
"\\\\*\\*\\*\\*.TMP"=dword:00000000
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\NetCache\ExclusionErrorSuppressionList]
Never had much success with that TBH!
But this does the trick, it tells the syncer not to notify unless there is an error!
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Syncmgr]
"KeepProgressLevel"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Syncmgr]
NOTE: The KeepProgressLevel Value Name can have the following data values:
1 - Pause on errors.
2 - Pause on warnings.
3 - Pause on errors and warnings.
4 - Pause and display INFO.
From: http://forums.msrportal.com/archive/index.php?t-21514.html