debugging on the server

Hi,

This is not your typical WO admin question, but my reason for asking 
you will be clear.  I am using my OS X server host for development.  It 
is so much faster and mostly sits idle, so I decided to tap the unused 
horsepower.  The problem is that invoking the URL to my app through the 
apache webserver, on the same machine, fails.  Meanwhile this works 
fine from my OSX client iMac, just much slower.  The URL I invoke looks 
something like:

http://[ IP ]/cgi-bin/WebObjects/[AppName].woa/-[Port#]

and it fails with an error something like:
"Safari can't open the page 'blah blah as above' because it could not 
connect to the server [IP].

I have tried using 'localhost' & [hostname].local & [hostname] in place 
of [IP] with the same results.

Could someone please explain what it is that makes this fail on the 
server yet succeed on the client and how I might overcome this problem. 
  The webserver, httpd, is running, I am sure, so it is not that.  Any 
input would be greatly appreciated.

Thanks,

-Brian