Help Game timing out! while online playing

[SpudGun]

Hi everyone Please could someone help? Had a problem for a while now and have had a few problems finding out whats causing it.

Problem is I join game through hyperlobby no problem then after a minute or two sometimes a few seconds, I get a 'disconnection from local host, reason timed out' message? did all the usual things port forwarding, DMZ, switched off firewall etc, even changed routers, but still the problem persists? I have one pc on my network so no problem sharing, also wirless is switched off. while I'm playing online everything is fine and the play is smooth, so this problem is really bugging me!

Any input from network Guru's much appriciated Thankyou?