Ok, just for the heck of it, can you start a new thread with a new topic title. Title it something like CGN3ACSMR signal check. Log into your modem, navigate to the STATUS......DOCSIS WAN page, copy the downstream and upstream tables and paste those into the new thread. Or, you could just paste those tables into a pm and send it to me. Either one works. This is just to make sure that your cable signal levels are ok, and not presenting a problem when it comes to finding your modem for the update.
Just sent a request in for the firmware update. Hopefully this fixes the issue.
Also, there are similar connectivity issues with Ultra Street Fighter 4 and some other Steam games that connect P2P. Never had any issues on my old Rogers modem. I'm not sure what exactly causes these issues since the Firewall on the gateway is supposed to be turned off.
Thought you might like to know.