System attendant stops

[XIanMacX]

For the last few day, all my exchange service stop starting with this event....

event id 7009
Service control manager
Timeout 30000 milliseconds waiting for the microsoft exchange system attendant to start.

followed by event

event id 7000
Service control manager
The Microsoft Exchange System Attendant service failed to start due to the following error:
The service did not respond to the start or control request in a timely fashion.

I then have to reboot the server and after a few more minutes the same thing happens again....
What could be going on?

Thanks in advance
Ian