Yes that's the way it looked but it was Colin that hit the nail on the head! Sometimes Vista can be a real pain!
Apparently, if you install the driver with the User Accounts feature turned on, the driver is loaded where Vista can recognise it (but perhaps the program can't access it). I suppose that the way to get around all this is to install somewhere other than in Program Files (which is what the FAQ really suggested).
Anyway, thanks to some splendid help, I am now able to connect on both machines. Thanks again, fellows.
Geoff