loosing mouse while resizing gtk3 windows

[de-bug]

When I'm trying to resize gtk3 window with mouse there's a big chance to loose mouse completely - no usage of mouse is possible anymore, only cursor shows. Maybe the bug is connected with standard gtk3 resize area in lower right corner of app. The only solution is to kill gtk application. It seems to me that there's a rare chance to get this bug with gtk2 app too.