The site is hosted on a computer on my network, and my router forwards webtraffic to that server. When somebody outside of my home network accesses the site, the get this:

When we try to access the site from inside the router, we get "page can not be displayed" type of errors. If we type in the IP for the server, we can access the site, and it'll look like the screenshot above. Though if we try to work on/with it, then we often run into the "can be displayed" errors again, because the ljconfig.pl section changes all of the addresses from the server's IP to the formal site name, which causes the faliure. Not so much help when trying to create journals or logging in, or other things like that.
Here are my ljconfig.pl and httpd.conf files:
LJConfig.pl
$DOMAIN = "_____.________.net:8989";
$SITEROOT = "http://$DOMAIN";
$IMGPREFIX = "$DOMAIN/htdocs/img";
Httpd.conf
Port 8989
User drew
Group drew
ServerName {Same as $DOMAIN in LJConfig, but without the port numbers}
PerlSetEnv LJHOME /home/lj
PerlRequire /home/lj/cgi-bin/modperl.pl
So my questions to you are:
1) Why does my site look the way it does?
2) Why isn't my site operating like I expect it to?