Vista laptop "forgets" how to share printer

Hi,

I have an HP Desktop running XP Pro (SP3) and a Dell laptop running
Vista Business (SP1) with a Linksys home wireless network. The
printer in question is an HP 932c attached to the desktop. Both
computers have the same current version of Norton Internet Security
running. (I know, I know, no lectures please. <grin>)

Using the tips here, I have no problem getting the laptop to share the
printer using the trick of installing it as a local printer and then
remapping the port. Works fine, every time, until I shut down the
laptop.

When I restart it, the remapped port which I installed has vanished
from the list. I need to repeat the process again, and it will then
continue to work normally for as long as I keep the computer on. I
can put the laptop in standby, and it will come up working normally.

Any ideas on what is causing the laptop to delete the port? The
desktop and network are always up when I start the laptop.


--
Alan