Web Site stops for no apparent reason.

I have a particular web site which at one point was being stopped by HC7 for going over disk quota.  I have updated the disk quota, and also set the server to "Do Nothing" when the quota thresholds are reached.  But now the site is being stopped still at midnight the last 2 nights, after some period of no trouble.
How do I prevent HC7 from stopping this site under ANY circumstance?

Check in the IIS --website---properties --- ISAPI filter and if there any filter been added by the control panel then remove it.

By the way HC Disk quota service take such action to calculate disk space for hosting services, try to disable the service and find out the conclusion.

No ISAPI filters here.
 
I'll try disabling quota service and see if the problem disappears, that will at least narrow down whether the problem originates from Quota.

I remembered this issue we faced in HC7 which was resolved by support, but right now we are using HC8 and never faced such issue again till then.
 
You should avail the HC 90% promotion to upgrade your servers, as we have already secure many HC keys :)

I have just started experiencing this issue the last couple days.  All sites under a webadmin are being turned off!!  I have submitted a ticket with support but I thought I would post here and see if the community had an answer?  Our server windows 2008 using HC8.
 
Any help would be greatly appreciated!

Check the event viewer maybe application pool crash under which the website is running.
Or maybe user have stopped the website in domain :: properties of domain.com 

Thanks for the info Andy.
 
I've seen the application pool crash issue before, but there are several other sites running under the same app pool so I'm certain that isn't the issue.
 
We have changed the users password in the event it was the user, but that did not resolve it either.
 
Just as a temp fix I have raised the affected domains limits to confirm if it is the quota service stopping them (even though its set not to).
 
Has any body else experienced this before?
 
Thanks guys.

This link may help you:
http://portal.hostingcontroller.com/KB/a54/website-stops-automatically-in-the-server.aspx

Thanks for the link Xavier.  Unfortunately we have already rulled those out of the issue.
 
Still working with support to resolve this issue, will post any new info when received.
 
Thank you everyone.

Just a final note...
 
Support had to remote in to the server and fix and issue with the limits.  Apparently, even though the correct limits and "do nothing" was set, this wasn't actually being applied.

Thank you everyone for your help.