Fonts disappear from Office apps after reboot but remain in OS??

So - I'm at my wits end - any suggestions would be appreciated!!

On an XP SP2 machine with Office 2003 SP2 we install a true-type font and it
works just fine. We can see it in Fonts folder as well as use it in Office
products. We logoff/login - same thing - works fine. We restart system -
this font is no longer available in Office products but are still visible in
Fonts folder. This happens with many fonts that we install - so it's not
font specific.

We've rebuilt the device twice and the problem reoccurs for this pocket of
users. We've had them login to test machines and it works fine (ruling out
ID related issue). I've logged into his machine and had the issue
(generating a new local profile). So - we think we've narrowed it down to
their physical devices with a physical reboot.

From reading another thread re: fonts, I did confirm the registry of the
device does have the Fonts key and does contain all the fonts. This problem
is specific to the applications (Adobe and Office) not being able to see/use
the fonts after a reboot.

Has anyone come across something like this? Any suggestions where to start
troubleshooting further?

Thanks!
Michelle