samba - Jul 2006 - Changing file mode "behind the scenes" doesn't show up

I have a XP box mounting a share from a Samba server.  I create a file
on the share via the XP box.  The XP Properties dialog for the file
shows that it is read/write (the Unix side shows the file to have 744
permissions, as expected).

Now, on the Unix side, I chmod the file to be 544 (i.e. readonly).
Back on the XP side, however, the Properties box still shows the file
to be read/write.

Presumably something is caching the file attributes and eventually
Windows will "catch up" and show the right attributes.  My question
is: is there anything I can do configuration-wise to make this happen
faster?

David