My first suspicion is that Norton might be somehow blocking traffic after the installation. Did you completely disable Norton during the installation? If yes, then you might try uninstalling Norton completely and then reinstalling the Crimsons. I think this is the first time I've ever heard of this problem.
even with Norton completely disable, that wouldn't work...
What finally worked is moving cards from different slots. After several tests and reboots, i must found a good match because internet is back! It might be soem kind of interference between cards but my previous graphic card didn't react like that.
It's the first time something like that happens to me.
thx for the answer,