help! - NTFS network drive mounted smbfs has invisible files?

I have a Gentoo box an with up to date (stable) system load (kernel 2.4, samba
2.2.8) which mounts via smbfs in /etc/fstab a public network drive on my
company's LAN. This drive is on some kind of NT server. I've had no
problems with this up until today. Now, all of a sudden, some of the files
in one directory (and only this one directory) are invisible to the Gentoo
machine.

By this I mean that 'ls -la <ntfsdir> shows some - but not all - of the
files. There is not a permission problem - I created the files (from the
Gentoo box, actually). I can even create them again, but as far as the
Gentoo machine is concerned, they don't exist.

I can see them, open them, etc. from a Windows machine. I can also see and
open them from a RedHat 9.0 machine mounting this directory the same way.

I tried creating another directory on the drive from Windows and copying
these files to the new directory. When I did that I could see them from
the Gentoo box. So I moved all the files from the one directory into the
new directory. I could still see them. Then I deleted the old directory
and renamed the new one what the old one had been named. Now the same
files became invisible again. Unfortunately, I have no control over that
directory - it has to remain named as it stands.

I am completely stumped. Does anyone have any idea what might be going on?

Here is the way I mount the directory:

//<IPaddr>/groups /home/groups smbfs \
credentials=/.smbfscred,uid=1002,gid=100 0 0

-Jeff