Home Hub issues??

[#1]

I set up a friends network about a year or so ago, who had got BT Broadband and a home hub. He recentrly got a laptop, and wanted it wireless. I set this up for him, relatively painlessly, but noticed the wireless range is very poor. He does live in a rather old house, a converted farmhouse, but we cant get any wireless signal upstairs, at all, and to cap it off when you do get back in range of the router, it takes an age to re-establish a connection.  I have tried everything I can think of, changing channels, looking for the wireless power, but seems to be no option to boost. Works fine in the room where the router is, and in other rooms on the ground floor, signal seems to degrade as soon as you leave the router room. Hes does live out in the sticks, so ADSL speed is poor (708 downstream sync!!), but there are serious issues with his BT wiring, but this shouldnt affect wireless speed. Is there anything else I can try, not ever tried Plug networking, and have no experience with wireless repeaters, and how could I find out where to put the repeater. Is the homehub any good even, and if not, can BT broadband be used on a non BT router. I am trying to persuade him to move to Plus, but in the interim I would welcome any advice.

[#2]

If its an old Farmhouse with Thick walls, you can kiss your WiFi signal bye bye, they dont like even thin walls

[#3]

Thanks I think
Have you any experience with HomePlug networking or wireless repeaters. Is netstumbler any use in these kinds of situations?.
Their BT wiring really is an issue, the router is next to the PC, in a corner surrounded by 2 walls, one external, connected via a flimsey extention cable. Cant really move the router at the min as the BT wiring is in such a state, I even recommended they get BT out. They appear to have 2 master sockets!!, and masses of phone cabling, I would not know where to start. If we can move the router to a more central location, may have a better chance?

[#4]

I am lucky as I have two battery operated devices Archos 705 and EeeePC that both have WiFi meters on them, so I can walk round and see what the signal is doing, never had to worry with my home set up, but when I was staying near St Austel The block I was in had 2ft rock walls, I could see the main building through the window, but no Wifi until the set was on the Window ledge.
Old wiring can be a problem, you ask Shutter and the rest of the mob who helped him sort it out.