E8604 on Exchange Agent

[microkid]

This is driving me crazy! We have W2K domain, with a W2K exchange 2000 server. Exchange agent for Exchange 2000 is installed. The full backup at 23:00 goes well, but the differential backup at 12:00 fails: E8604 "DBname=\individual mailboxes\ (429) Fail to open information store."
I cannot access the bricklevel in Arcserve since then. It worked fine yesterday.

Any clues?

 

[TheLad]

Could it be that these files are in use so they cannot be opened by Arcserve? At 12 midday it could be likely? "It's true, its damn true!"

 

[microkid]

Nop, because it used to work fine, and even at 23:00 the files are in use because Exchange is still running...

 

[SFTechie]

Could it be you have the same mailbox listed twice?