Graphite Base station connects -Snow doesn't

[stilbite]

I am running four Macs in the house via a graphite base station and an NTL external cabel modem. They work absolutely fine. I have acquired two Snow Base stations. My intention was to change one over and sell the other. Initially I could see either snow base station when simply plugged in but could not surf the net, 'connection was lost'. In time I have done a hard re-set on both stations, I have updated the lastest software and re-configuired both. I can still see the ABS' in my wireless icon on the top bar whenever I plug them in but still cannot connect to the net when accessing them. I have disconnecctd the Graphite completely and tried to use one of the Snow's connecting in exactly the same way, via an ethernet to the modem and re-booting in the set sequence, ie: turn all three off, boot modem wait, boot base station, wait and re-boot Mac. Still will not connect to the net but is all visible in the network configurations. Each time I have re-connected the Graphite.. it just connects and I have no problems getting back online. The main Mac is a 21" iMac G5. m I missing some simply key configuration or is the NTL cabel modem not compatable? Thanks, Jimbo