Random Server Application Unavailable error on production servers

[Undecided]

We've had 2 Windows 2003 Servers Web Edition running an ASP.NET 1.1
application in a cluster for the last 3 weeks with no problems. Last
night a few of our users started getting the "Server application
unavailable" error while others had no such problem. We are using ADS
authentication and in the Event viewer we can see the users log in and
out but some of them were getting this error message. Today they are
all ok. There are NO errors in the event viewer or IIS log.


Thanks

Constantine