Has anybody seen this "VBUSSyncExchange" event error??

[mysteryn11]

Morning all,

One of my exchange servers (2000) is coming up with the following error all of the time. Does anybody have any tips on what it means /how to get rid of it or fix the problem?
One of the other symptoms seems to be a message store crash, meaning I have to restart the IIS service every morning.

Thanks in advance! Here is the error..

[b]Event Type:    Error
Event Source:  VBUSSyncExchange (F0005)
Event Category:          None
Event ID:        1003[/b]

[b]Description:[/b]

The description for Event ID ( 1003 ) in Source ( VBUSSyncExchange (F0005) ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. The following information is part of the event: VbusSyncExchange was not able to access the information store (DefaultFolderCalendar). Calendar item will not be synced.System Error.: -2147221219 : You do not have permission to log on. [Microsoft Exchange Server Information Store –