I have followed along the tutorial and was able to get it to work. a few things you mention stick out to me:
using the DW Insert And Update behaviors, changing variable values in the recordset manually for example are things that will cause problems.
The MRT Behavior is designed to work with pages created by the data assist wizard, not with the DW Insert and update behaviors.
I am finding the problem report very difficult to sift through, so rather than go back and forth, I have created a support ticket so we can look into this issue further.
To view and edit your support ticket, please log into your support history:
supporthistory.php
If anyone else is experiencing this same issue, please append to this thread.