Schedule Tasks

Hi!
I'm having a problem with schedule tasks on a windows 2003 r2 sp2 server.

I have made a batch file name bat.bat and put the simple code of 'xcopy
bat.bat bat.bak'
This batch file I'm putting on another server \\srv2\share\

While logged on to the server as a domain admin ex DA1 I can set up the
scheduled task \\srv2\share\bat.bat and if the user credentials is DA1 I can
run the task and it works just fine.

But if I am still logged on to the server with DA1 and tries to run the same
task with another user, even if this user also is a domain admin ex DA2 the
task does not run
I have tried to add both DA2 and batch to the security to cmd and I have
also given them full ntfs rights to the shared catalog.
But nothing helps, what am I missing? or must I run the tasks as the person
logged onto the server?

I have also tried to run the task with the unc path \\srv2\dir\dir\bat.bat
but no dice