Can't Connect from same IP

[NinjaMidget]

My roommate and I play HL2 TDM...no problems connecting for months, but after the latest steam update, I can't connect if he's already playing on the server and he can't connect if I'm already on the server. Does anyone know why the hell that is happening and how to correct it? We both have legitimate store bought copies of HL2 and different steam accounts. It seems like it's not so unusual for people to play HL2 TDM from within the same house.

 

[Link]

Do you get an error when trying to connect, or does it just do that "Retrying connection" thing?

Anything else changed recently? New router? Anything like that?

 

[NinjaMidget]

Oh yeah, the error message would be a good thing to have, huh? It just says connecting for a minute or so then says it timed out after 4 trys. Nothing has changed with the router or any of the computers on the network