The majority of our 300+ NW clients are still using Client32 4.90sp1a and
working just fine. Turns out any of the 4.91 variants (all the way up to
including the most recent beta SP1 patch) no longer allow any executables
on my NSS volumes flagged with the X (execute-only) attribute run - all you
get back is "The system cannot find the file". I can move back to a
pre-4.91 client and the file still runs fine with the X attribute.

From what I can tell, no one uses that attribute in the world, except for
me, but I have one particular program on my server volume that I don't want
any user doing anything with it (copy, view the contents of, etc.) execept
execute it.

- Tom