Does anyone know how to have the tooltip to come up when you tab to that button?
tooltips only appear on MouseOver
You might be able to use OnObjectEnter (which can be set even for grouped buttons if you work around the interface bug that seems to prevent it), to make something appear (not an actual tooltip) when the button gets the focus. (note that clicking a button does not give it the focus, but tabbing into it does.)
Retrieving data ...