are u using the local ip or the remote ip?

some routers and switches cannot, unless set up correctly route the outside ip back to a local machine, so if you are using a domain name (eg wilfred.my.com)
try the local ip, if you still cant figure it out or you already tried it

what system are you running windows or linix

if its linux is it fedora core 8

if it i fedora core 8 do you have a domain name? fedora 8, by default, does not allow connections via ip

if none of the above, then i cannot help you

good luck