Server Application Unavailable - No entries in Event Log???

[Joe Schmoe]

Have an ASP.NET app that intermittently kicks out "Server Application
Unavailable" messages when in use by several users at once. The message says
to see the Application Event Log, but there are no relevant messages in the
event log. (No filters in place on the Event Log, get other messages in the
Event log, am even able to write my own events from the same app into the
event log, etc.)

Any ideas what could be causing such a condition where a "Server Application
Unavailable" does not write to the event log?

Thanks!