http://bugs.winehq.org/show_bug.cgi?id=13417
--- Comment #10 from Reinhard Berger geist1@sms.at 2009-09-20 01:18:28 --- I found out latly that the popup menu can disappaer when you press the space bar key.
It does not work when a tranfer is in progress, but when you do something (e.g. create a folder or send a raw command) then by pressing the spcace bar the popupup menu will disappear, and the mouse is then working again.
This is a realy nasty bug and i hope it will be fixed soon.