(file-exists-p) bug?

[Doug Lewan]

I'm running emacs 24.3 (2013-08-20 build date) on CYGWIN 64 bit.  There are 
file systems mounted with OpenText NFS client from an AIX box. 

(file-exists-p "/cygdrive/q/file/of/interest/.dir-locals.el")
=> t
where the /cygdrive/q/file/of/interest is a regular file.
The same does not happen with files of interest that do not exist:

(file-exists-p "/cygdrive/q/bobtcat")
=> nil

I've looked through the help-gnu-emacs and bugs-gnu-emacs archives and (in the 
first 5 or so pages) don't find anything like this. It seems like a bug, but I 
always assume that I'm doing something wrong first.

Does anyone know what I might be doing (have configured) wrong?

Thanks.

,Doug
Douglas Lewan
Shubert Ticketing
(201) 489-8600 ext 224

Hazmat condition: There's some emacs on the floor.