I have a roaming profile issue that I would like some clarification on...

I recently set up a new user and forgot to enter the path to the roaming
profile in his AD profile before logging him into one of our XP machines he
will be using for the first time. While I was logged on I proceeded to
configure his desktop the way he needs and when I finished, I remembered
that I had forgotten to set up the roaming part of his profile. So before
logging him out, I added the path to his ropaming profile in his AD profile,
saved it,  and then logged him out of the XP machine.

I then went over to a differnt XP machine and logged him in to test, and
behold, the desktop changes I had made on the previous login were all
there - so I knew the roaming profile was working. I did not have to
configure any printers on his profile as the various network printers he
needed were already installed on that PC and as such existed in his profile
of the PC he was logged onto.

Now this is where it gets tricky... Yesterday he had to log back into the PC
I had inititially set him up on, and some of the printers are missing - yet
they are all installed on that PC because the main user of that PC uses them
all the time.  My question is, if the drivers are all installed on the PC,
then why wouldn't all of the printers show up in his profile based on his
roaming profile settings? Are printers not a part of the roaming profile at
all? - and even if they are not, why would all of the installed network
printers not show up anyway - when they are all installed on that PC? SOme
of them show up and some don't!!

Help!

Thanks, Brad