Intermittent Error 500 - Internal Server Error - Apache 2.0.54 / Tomcat 4.1.24 & Tomcat 5.0.27

Hi,

We recently had a server crash and we have rebuilt it from scratch. We
have installed Linux 2.4.21-4.ELsmp and have setup Apache 2.0.54. We
currently run 5 separate instances on Tomcat, 1 instance is run on
Tomcat 5.0.27 and the rest are run on Tomcat 4.1.24.

The problem we are having is that intermitently (quite regularly) you
get an error page - Error 500 - Internal Server Error - displaying the
standard windows - Page Could Not be displayed error page.

We have Error 500 pages setup for both Tomcat & Apache but it is not
either of these pages we see, it is the Windows version. If I stop the
server I can see the Apache & Tomcat configured versions so they still
catch when the server is down.

This is becoming a nuisance because customers are calling up regularly
now and all it takes to fix it is a refresh... You can sit at the desk
and continuously hit refresh and it can go down 2/10 times...

I have checked the Apache & Tomcat logs and there is no register of the
access at all in the access log or the error log!!!

If anyone has any suggestions as to where I can start looking I would
appreciate your feedback.

Thanks
Shannon