value-input issue in Minefield dialog

[eclair]

(Build 1147.45) "Create minefield in designated area" dialog cannot directly enter the number of mines, and have to use add/decrease button only (you can add 5-10 mines, but adding 500+ of them is simply impossible).

I'm not sure this has something to do with keyboard settings or so, but you can request any furthur informations.

.save attached anyway.