Scheduled Task Permissions

I have a scheduled task that executes an exe that essentially creates new
files on another server, moves the files to different directories on that
same server, logs the results, and sends me an e-mail with the results of th
e
run.  The problem I am having is that I receive “Permission Denied” erro
rs
when the task runs as scheduled.  The program launches, it writes to the log
,
sends me an e-mail, but it cannot create or move any files.  (The account I
use to run the scheduled task is a domain account and the account has
Read/Write/Modify permissions on the directories where files are created and
moved to.)

I can logon to the server with the account I use to run the scheduled task
and manually run the exe with no errors.  I only get the errors when the tas
k
runs on it’s own as scheduled.

If I configure the scheduled task to run as a System Admin account, the
scheduled task will run on its own with no errors.

Does anyone have any ideas why I would receive errors using anything less
than a System Admin account?