MDC reboot causing OD crash

[Hitman]

I'm experiencing some issues where my OD server crashes when I reboot any of my MDC in my XSAN architecture. The SAN keeps working as it fails over to the other MDC, but my OD hangs indefinitely and needs to be rebooted to be functional again. Here is some additional info about my architecture:

MDCs:
- I have 2 MDCs.
- Both are running on Apple XServes
- Both are running Snow Leopard 10.6.8
- Both are running XSAN 2.2.1.

Directory Services:
- I'm running OD and AD in a "golden triangle" infrastructure and it works well.
- The OD is running on an XServe running Snow Leopard 10.6.8.
- The AD is running on a Windows 2008 R2 server.
- The network homes are stored on a volume on the SAN.
- We have a replica of both the AD and the OD.
- The MDCs are bound the the master AD and OD.

When I reboot any of my MDC (after a software update, for example), it makes the master OD "beachball" and unresponsive. I have to reboot the OD to have it working again.

Does anyone have any clue what could be happening here? I can't find anything significant in the OD logs.

Thanks.