Application poll shuts down after warmings in event viewer

[RobertS]

In my eventlog I keep getting warnings which I cannot explain.

A process serving application pool 'domainame.com(domain)(pool)' suffered a fatal communication error with the World Wide Web Publishing Service. The process id was '1188'. The data field contains the error number.

And after a whwile the application pool shuts down with an error in the event viewer like this:

Application pool 'domainname.com(domain)(pool)' is being automatically disabled due to a series of failures in the process(es) serving that application pool.

This only happens with this application pool. Could please someone tell me what this causes and how to fix this?