Windows – Troubleshooting ‘Windows ERROR — Possible Deadlock Condition”

You're out of named properties for your mailbox store (see Jason Nelson's very funny article on named properties at the EHLO blog). This problem was just fixed in Exchange 2007 SP1 rollup 8, but that doesn't help you because you're on Exchange 2003. You can adjust the limit used for the named property list by following the directions in MS KB article 820379 (it seems to have been pulled but you can find a copy here).

Here is a Microsoft KB reference to start with,
"Directory Services cannot start" error message when you start your Windows-based or SBS-based domain controller.

Have not looked deeply in your other questions, and, i do not see a reference here suggesting you have done a Microsoft KB lookup.