It also could be interference from other routers, try changing the channel
I've cut and pasted the procedure below I hope it makes sense
To change the channel :-
Connect your laptop to the hub using the Ethernet cable.
Open Internet explorer and type in the address
http://192.168.1.254.
Left column choose Advanced
Next page ‘continue to advanced ’
Next Page choose ‘switch to other user’
Next Page user name and password are ‘admin’
Next Page left column choose Home Network
Home Network
Wireless
WLAN: BTHomeHub-00A1
(54Mbps)
Look for above diagram. ( it will have your hub name) . Click it.
Next Page left column choose Interfaces
Interfaces
LocalNetwork
ethport1
(100Mbps)
ethport2
(100Mbps)
usbport
(12Mbps)
WLAN: BTHomeHub-00A1
(54Mbps)
Look for above. Click on the WLAN for your hub.
Next Page top right choose ‘configure’
You have arrived at the WLAN tinkering page.
Choose ‘Interface Type’
Change from 802.11 b/g to 802.11g ( only if wireless card is g)
Choose Channel Selection. change from ‘ automatic’ to ‘manual’
Channels to try are 1, 2, 6, 12 and 13. ( these are the preferred channels)
Click Apply. Check to see if it has made any difference.