Lebans MouseWheelOff and scroll in textbox in subform

First thing first:
MouseWheelOff is an excellent extention to Access.
For users used to scroll in textboxes with the mouse wheel access
applications can be a nightmare.
One little scroll and poff your data are "gone".

Then to my request/bug-report:
I can't scroll in textboxes placed on subforms.

To recreate this behavior, open the demo access mdb in the
MouseWheelOff.zip. Open the form frmsuddata and change the Stuff
textbox to multiline with scrollbar.

If you now run the frmSampleData and turn off the mouse wheel you will
be able to scroll the textbox up to the right, but the textboxes in
the subform will not scroll.

Is it a bug or by design? Or is it something I have missed?

Best regards
Ove Halseth