Helo all!

A wierd shift-key problem, for which all I found was sticky keys answers First of all, I have all the sticky keys and related, Disabled.

Every windows that is currently in focus, if I press the left shift-key alone, pops up the current window menu. I have no idea how and why this has happened, or how to disable it. I could not find any reference in google about it (perhaps my search-string was not good..) any help would be appriciated