I am on Telewest but people here are complaining about incompatibility with ntl but that may be down to a bad batch
I don't have problems but it does seem to lose connection if I don't use it for a while (if I turn my monitor off and then **** off somewhere and then come back to see it's lost connection. And all I do is restart the PC).
Distance - I use a WMP54GS client card which is in the next room and I get about somedays 11.0Mbps, 18.0Mbps, 36.0Mbps and 54.0Mbps (this is what it is mainly) The low Mbps must be down to interference or something from other routers in the area. I can see about 7 in my search.
Try one of next generation one from Netgear - DG834N, it has good review and highly recommended.