Serious problem here lads, Please help meh!

[Merlin4458]

Basically we have 3 on a lan. Going through a 1mb and a router vigor 2200 USB. Since weve been on the lan we have had no problems at all. But all of a sudden this happens.
If im playing counter strike source on a server and non of the other 2 are. My ping is fine, but as soon as 1 of the other 2 joins the server or another server, the ping goes from 40-2000-40-2000-40-2000. This is going on the whole time. Then when one of us stops the ping is fine again. We dont have to be on the same server jsut as long as were palying the game at the same time.
We have done online panda scan, home call scan, bit defender pro plus scan, avast scan, adaware scan,spybot scan,micrsoft beta scan,spy sweeper scan, and nothing special has turned up

Any ideas?

[Merlin4458]

anyone,,,,,,,,,,,,,,,no.................dust?

[Matt1eD]

If it were happening only when you joined the same server I'd say it was something to do with the IP being shared, otherwise, sorry dunno. Computer says no.