Comment 3 for bug 630193

I'm having the same problem with the ThinkPad X41 Tablet when trying to use the stylus on those buttons. It seems to me that the problem has to do with the fact that the buttons can be dragged and since using the stylus most of the time generates some movement even when just clicking I think the click is being treated as a drag.

I think Unity needs to have a threshold or null zone for this drag function on these buttons for tablets.