Cant see anything on Microsoft technet for this code with Outlook, but it is mentioned for configuration manager where it mentions out of cache. :-
http://technet.microsoft.com/en-us/l.../bb632794.aspx
Dont know if MS error codes are consistent across apps. Which version of outlook are you using , if its pre 2007 you could try an upgrade ? Backup your files before attempting this though in case it goes wrong. If your on 2000 try upgrading to 2003.
Are you able to try outlook express and see if it has the same problem, id try that before an upgrade ?