It looks like you lose your internet connection, and that is why you get disconnected from the BBO. When that happens, the DNS entry in your local resolver in the router has expired, so when you try to reconnect, the OS tries to resolve the name again, but fails. As TylerE said, you only need the DNS on connecting, so it can't be at fault. And you discovered that yourself when you changed the DNS server settings to Google. Take a look at the LEDs on the cable modem before and after you get disconnected, and talk to your ISP. They monitor the connection on a lower level, and know when you are disconnected. Once they establish that happens, they should be able to get to the root cause, and possibly fix it. If they can't or won't, change your ISP.