it's generally around the evening, right now it's working fine, I get the odd d/c but it comes straight back up, which is annoying but yeah I just chalk that up to using a wireless connection, but in the evenings around 10-11pm it just cuts out completely, the wifi light is still on on the homehub but none of my devices can find it.
1) When this happens at 10-11pm can you connect to the internet by ethernet?
2) You say you have tried 3 different home hubs. Does it happen to all of them?
3) Make sure the BT Power Save on the HH3/HH2 is off
4) Make sure that the BT Access Control is off
5) What colour are the hub lights when this happens?
6) What is your home hub by/next too? Any other electrical appliances, on window sill? As there may be interferance.
Any thing that switches on at around the same time as you loose wireless connection?
The problem you are having is similar or almost the same to the one I am having. http://community.bt.com/t5/BB-Speed-Connection-Issues/Hub-strange-behaviour/td-p/557219
with the difference that I lose ethernet connection too. At the moment it seems to be that the router's wifi overloads or jams easily and makes the whole router unusable. I have done a factory reset on the 'router' and switched to channel 11. It has been working fine for a day(apart from my broadband service loss for 1 hour last night!)
Use your Xbox with your ethernet as they sugested you before because it is more reliable, less lag and that.