Hope someone can help me here. I'm a Virginmedia broadband user with the superhub2 in modem mode. My router is a 2860n (firmware 3.8.2_VT2|), a replacement for a 2820n purchased when I thought the router was the cause of my internet connection dropping.

I get around 70-80 Mb/s on a speedtest.net test, but now any download through Steam crashes my connection instantly. Neither the router nor the superhub web interfaces can be accessed, one or the other (doesn't matter which) needs to be powered off and back on in order to restore connectivity. I've set the download throttle in steam incrementally from 16Kb/s up to 512 Kb/s and the connection seems stable. Going up to 1 Mb/s or higher will kill it.

As far as router config is concerned it is pretty much in its shipping state - all I've done is configure WAN2 and disable WAN1, and enter VPN details for connecting to the office VPN. No DoS or bandwidth limits have been set. Connecting my PC direct to the modem allows unlimited speed downloads from Steam - peaked at about 20 Mb/s this morning. Anyone got any idea what the Vigor dislikes about the way Steam handles downloads?

Have you tried turning off Hardware Acceleration?

Thanks for the suggestion, I have now (I think), but it made no difference. I'm not certain that I'm switching it off correctly though - the main menu item for hardware acceleration was set to auto, switching to disabled made no visible difference to the config displayed. Selecting manual allows more changes to be made, but I don't know what I'm doing in there so I just set it to disabled, rebooted the router and tried again. Same result, immediate loss on connection.