If in the HarnWare Options menu both the “Tool Tips” and the “Always on Top” options are selected there’s a conflict for what actually gets drawn on top. In the case of the toolbar it, rather than the tooltip, wins. In most, if not all, other cases I believe the tooltips are displayed correctly.
As far as I’m aware this is unfortunately a “feature” of Microsoft Windows which affects a number of programs and which is something over which we have no control. To add a further twist I believe some versions of Windows are affected whereas some others are not.