Have you tried connecting the lappy by wire method first? This will bypass any wireless encryption issues.
I'm also running through a Linksys router and NTL SACM but to be honest I didn't use/need the included software.
If you power down the PC, modem and router, then Switch on the modem.
Leave for Sync and ready lights to stay on.
Switch on router (till lights stable.
Power on PC.
Then Power off everything, then connect the lappy wirelessly and power up again.
You should find the connection has been made (as if by magic) The only net connection problems I had was when it came to the SSID and WEP stuff.