Callback not working from DD wrapper script

System

I've been fiddling with this for a day now and I still can't see what I'm doing wrong. Can please someone help me before I loose all my hair.
I call a wrapper script from my workflow that does a DD and an OD and then callsback with either 0 or 1 depending on the success of the OD or DD. The Callback 0 works fine but I can't seem to get the Callback 1 to do anything. I include my WF and scripts for your perusal. Many thanks in advance for any help here ! BTW its TS 6 on Windows