failure to connect / Linksys card

Hi all, strange problem. I brought home a colleague's laptop (Toshiba
Satellite - older model PIII) in order to reinstall XP SP2 for him as he was
having all sorts of problems, including conflicting drivers and partial
uninstalls etc etc.
Now, he has a Linksys 54g PC card which I set up with the sw from linksys
website and it installed without problem, easily accessing my home wireless
network. I thought that to connect at work would be a doddle - but though my
own laptop connects there, his continually fails to establish a connection.
I have tried using the linksys sw and also disabling this and using XP WZ
config. Obviously, I have ensured he has exactly the same settings as mine
(IBM Thinkpad T43 2GHz Centrino XP Pro SP2).
Any suggestions as to what to check out first?
TIA
Rob