FS7600 Cifs share command prompt issues

Greetings,

We have a new FS7600 NAS connected to our PS6500.  Joining the domain, setting up cifs shares and copying data to it all took place smoothly.

The problem we are experiencing is strange responses when accessing cifs shares from a windows command prompt.  Performing a simple 'dir' command will produce different results when run repeatedly  - one time it shows zero files, then all the files, again zero, or somewhere in between.  Results are always immediate, there is no lag waiting for a response.  When viewing the files in Windows Explorer this does not occur.  We have tried a few other command prompt applications (tcc from jpsoft) and get the same results. 

Any suggestions?  Thank you