Bug in buttonless Window

[Johannes Schaback]

Hi Boris,

I just received a mail from a user who found a bug with Window when
using no frame-control buttons at all. I was hoping that you may have
the time to fix it? :)

http://sourceforge.net/tracker/index.php?func=detail&aid=1628227&group_id=178317&atid=884747

Thanks in advance :)

Johannes