printer sharing problem

[Gary Kirkpatrick]

I have a Dell notebook 10 connected to a Canon printer.  I have a HP
laptop running 9.1/Vista.  I have enabled printer sharing under
admin/printing/server.  I can not print from HP from ubuntu nor Vista
(which half the time can not display the notebook's contents anyway).

This arrangement has worked before- I have been able to print from the
HP.  I can transfer files back and forth between the Ubuntu computers.

There is a wireless router.

Thanks for any assistance.