It was a bit more complicated than that, I'm afraid. Turns out that $GET should have been, at the time, $GET['tempID'], but what happens is that the value of $GET['tempID'] is an encrypted string that points to a particular $SESSION variable that is an array of items that are meant to repopulate $POST. However, there was a slight naming convention issue and that wasn't happening, and resulting in $GET being empty and thus the disconnect.
Thanx!
Phil