Google "A process serving application pool 'DefaultAppPool' suffered a fatal communication error with the Windows Process Activation Service"
The following links may help you to investigate:
http://forums.iis.net/t/1158869.aspx
http://forums.iis.net/t/1179493.aspx/1
Craig
The following links may help you to investigate:
http://forums.iis.net/t/1158869.aspx
http://forums.iis.net/t/1179493.aspx/1
Craig