Disappearing server shares on specific XP/Office2007 clientinstallations

I'm running a Windows 2000 server SP4 with all the latest fixes. This
server is sharing files and printers. The clients are all Windows XP
Professional SP2 (dutch language) with the applicable patches
installed. The problem seems to specifically haunt laptop computers
that also have the new Office 2007 (also patched to Microsoft
standards) installed.

The clients log in, and have normal access to all the shares on the
servers. The server keeps it's shares up and running (none of the
clients with desktops or even laptops with no Office 2007 installed
have the issue to my knowledge), but atleast two machines somehow
'loose' the ability to review shares on the server. I do have a few
more machines with the XP/Office 2007 configuration I have not heard
any problems from, but then again, that might just be a matter of
time.

Opening the UNC path to the server yields just one or two shared
folders, and the contents of these folders are usually empty.
Accessing a missing share or printer through the UNC path directly
gives the notification that the share cannot be found of contacted.
All the printers and the rest of the shares are just gone on the
workstation. Going to a different workstation shows the shares and
printers to be available, so it can't be a problem on the server-side.
This is further staved by the fact that as the Windows XP client that
has the issue reboots, all the shares and printers are back up as
normal again, as if they never were gone to begin with.

It's quite annoying because it removes the ability of the user to
access network items, aswell as utilize network printers. I'm a bit at
a loss as to what may be causing this, and thus would like to submit
this thread to see if anyone could toss up some idea's of what might
be going on.