The cause for this appears to be a conflict between windows that want to stay on top. Tooltips always want to be on the top. But if like most of us do, you have the Taskbar set to be kept on top of ...

Stallions whose progeny performance statistics make them the top 100 sires nationally or among the top 25 leadings sires in a given state are listed with runners, winners, stakes winners, stakes wins, ...