Anything in the eventvwr logs? What service specifically is hanging and what symptoms do you see whats not working when this happens?
James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
You also can use Exbpa to see whether there is any errors or warning.
Thanks,
Evan
Evan Liu
TechNet Community Support