I had that problem - some kind of routing issue somewhere down the mediaone line.
After dealing with their insane technical support (which, in spite of my proof of it being their fault) insisted I
1. Power down all machines on my network.
2. Power down the hub, and unplug all RJ-45
3. Power down the cable modem, disconnect RJ-45 and COAX and wait 45 seconds.
4. Start it all up again
I almost wanted to kill them. I finally got an email from a tech higher up on the food chain saying I didn't have to deal with their cust. service and that my problem had been 'escalated'.
1 day and about 15 hours later - problem solved.
