in reply to Re^3: How to make a Tk::Button move/slide within a Tk::Table
in thread How to make a Tk::Button move/slide within a Tk::Table

I realized that I wasn't updating the row and col of $buttons$selectedButton in slideButton(). I added
$buttons[$selectedButton]{'row'} = $mRow; $buttons[$selectedButton]{'col'} = $mCol;

to slideButton() subroutine and now the blinking/left over widgets are gone...