You've probably tried the usual empty firefox cache etc.
Have a look on your server, use iptraf to monitor incoming connections, or "tcpdump -n port 8080" and see if any request from your client actually hits the server.
If not, then something in between is rejecting the connection. Your router? Upstream router? I have seen a few service providers start blocking port 8080 as its (incorrectly) associated with proxy servers.
Maybe a "netstat -nlp" to double-check your http is definitely listening on port 8080 as well as websites which you have checked are available.
I have got it into my head that somebody else asked this today, cannot remember where I read it though.