I've got the administrator account on my laptop and that's running XP Pro. I don't think there is any difference in XP Home that affects you having an account named administrator? Also printer sharing works fine for me
Have you updated the printer drivers in XP and 2K? I've had loads of bizarre problems before because the drivers were a few revisions old and kept hitting bugs. In the end I got tired of having to power on my desktop every time I wanted to print so I bought an ethernet print server instead.
Anything in the event viewer about dud devices or errors?
Sorry, it's not very helpful as it's another "Works fine for me" occasion but I can't think of anything obvious you've missed.