Well, I did say "and that might not be enough" ):

The scheduler may start jobs in a different security context than its own (you did stop and restart it, right?) and then you can be "domain admin" but have a security context that allows no net access.

You could look for configuration options in the scheduler to see if you can configure what type of security context it lauches its jobs.

You could skip using the scheduler and just have a Perl script running as a service.

You could try using Win32::NetResource to specify a username and password to the share in order to access the files.

You could try the LogonUser() and CreateProcessAsUser() thing.

You could also do some debugging to figure out where the script is dying. For example, redirect STDOUT and STDERR to a file inside a BEGIN block at the top of the script and print status messages.