One thing the majority of HomeHub users may not be aware of, is that the default wifi channel is channel 6.
Now, with only 4 non-blocking channels in 802.11g, and the proliferation of HomeHubs, all on channel 6, if you live in wireless proximity of another HomeHub user the chances are you've got rubbish wifi functionality as a consequence.
In order to fix this, go download a wifi sniffer onto your laptop, such as Airmagnet, and check the channels and their associated strengths. Channels up to 4 channels either side of someone else's channel will interfere, to a greater or lesser degree, so if you choose channels 1,5,9, and 13, and choose one of those which is furthest from the majority of your neighbours, then you should see a corresponding increase in your wireless reliability