Matlab behaving erratic when accessing files over VPN

I'm not sure if this is a Windows issue or a Matlab issue, but I'm observing erratic behavior when I try to access files, using Matlab, from a network location over VPN. I'm using Matlab 2014b in Windows 7.

For instance, I have the code

filename_on_network_location = '\\mycompany.com\data\input.txt'
file_exist = exist(filename_on_network_location, 'file');
if ~file_exist
   file_exist_new = exist(filename_on_network_location, 'file');
   fprintf('Original : %d\n', file_exist);
   fprintf('New      : %d\n', file_exist_new);
   if ~file_exist
       error('file really does not exist');
   end
end

which can print

   Original : 0
   New      : 1

I have similar issues using the built-in dir command. I'm still checking to see if this double test gives a good workaround, but obviously I don't like it.

[Walter Roberson]

Shouldn't the second "if ~file_exist" be a test of ~file_exist_new ?