change volume when mouse over taskbar is buggy

using V4.4.5. win7 64bit
change volume when mouse over taskbar is enabled.
but it is also changing when not over the taskbar.
- click an empty space in the task bar (to make it 'focused')
- mouse over somewhere else that is not the taskbar
- scroll mouse wheel
result: volume changing
expected: do nothing, change volume only when mouse over the taskbar

TNX.