How to turn off mouse focus?

[Hans]

Learning Perl/Tk often talks about keyboardfocus, but not much about
mousefocus. On page 303 a method is described to use focusFollowsMouse, but
I want to do the opposite: I have a scale widget who should not get
mousefocus when the mouse is moved over it. Moving the mouse over a scale
widget causes the -command flag to be executed with every movement, even
though the value of the scale is not changed.

Anyone any thoughts on how to do this? Thanks for the help. --Hans