I upgraded to a Home Hub 4 after having some problems with the HH3 and I'm finding that while it works OK most of the time, it drops the connection after a couple of hours with Windows reporting that "no internet access is available".
If I choose "Troubleshoot problems" on the network icon in the notification area, it always comes up and says that "the default gateway is not available" and then fixes the problem. This didn't happen with the HH3 (despite other issues). I have full signal strength and this happens on both wireless and WiFi. The Hub 4 has been replaced and the same issue still happens on the new one (and with multiple computers).
Does anyone else have this issue? It strikes me that the might be a bug or firmware issue with the Hub 4?
do you have your network/wifi cards set to allow windows to switch off if not in use?