had the same problem, unfortunately there is not too much you can do to prevent the errors happening. but you can disable the logging for those, see google for "trickyponywindows" "outlook-2010-sync-issues-folder-is-full" (sorry this forum does not allow
me to add links).
Key: HKEY_CURRENT_USER\ Software\Microsoft\Office\14.0\Outlook\Options
DWORD: EnableConflictLogging
Values:
0 = Never save Modification Resolution logs
1 = Always save Modification Resolution logs
2 = Save Modification Resolution logs when a "critical conflict" occurs
<This is the new Default behavior when the EnableConflictLogging dword does not exist.>