2k connects to XP files but not printer

A friend of mine has 2 computers – XPPro SP2 and 2K Pro SP4. Both computers are on the same workgroup, and can share folders between computers just fine.
BUT – there’s always a ‘but’ – the 2k machine can see the shared usb printer on the XP computer, but can’t print to it.
We have checked user accounts – XP is using the username ‘admin’ with no password, but the administrator account has a password. The 2k computer is logging on as ‘Administrator’ and uses the same password as the XP computer’s Administrator account.
The XP firewall is disabled, simple file sharing is disabled and ‘everyone’ has full access.
There is no error message – it just takes a couple of minutes for the printer to even go from ‘opening’ to ‘ready’ when you highlight it in the printers folder.
Any ideas would be much appreciated.