Windows Easy Transfer, XP to Vista, and Belkin's transfer cable

Hi, I was asked by a friend to help transfer his files, settings etc. from
his old Dell PC running XP to his new HP PC running Vista. He'd purchased
Belkin's transfer cable for this purpose.

Well, I did get the two machines to see each other, and got as far as
selecting which folders I wanted to transfer. When I try to start the
transfer, though, I get an error message and WET has to close on the Dell.

Any ideas what to do? The only thing that comes to mind is that there's a
problem with the names being different on the user accounts, although I had
the impression from the WET prompts that that should not have been a problem.