Windows 2012 Task Scheduler won't run CMD script properly using a specified user account

I have a problem where the Windows 2012 Task Scheduler won't run a CMD script properly using a specified user account (user A), but will run properly using another user account (user B).  I specifically include the word 'properly' because in the first instance, the script runs successfully as user A (according to the Last Run Result), it creates a 0 byte log file and then quits without writing output to the log file.  Same thing when I run the script using the local system and administrator accounts ... 0 byte log file and no output.  Yet, when I run the same script as user B, it works perfectly fine, writing output to the log file.  I know it may sound like permissions, but it's not, as both user accounts have the exact same permissions and the 'Log on as a batch job' right.  In Windows 2003 server, the same script runs fine as both users, and as local SYSTEM and local administrator.  The log file get's written to a local folder at c:\dss\syncscripts.  

On the 2012 system, I can run the script directly by double-clicking it, and it works fine for any account that has permissions on the folder and "log on as batch job" rights.

Anyone have any pointers?

Thanks.

PJ.