When pressing the "Apply" button on the help control
popup window, the respective form field on the issue
being edited wouldn't get updated.

My fix was to edit help_control.js and declare the
field parm on the javascript tag near line 11, so it
contains:

field  = '${property}';

right below where the 'form' var is declared.

Not sure if this is the right fix / portable fix /
whatever. It "just works here" (TM).

Btw, thanks Richard and all other collaborators for
this great piece of software !!!