EditingReturn eventhandler not working on windows

Hi all,

the EditingReturn eventhandler does not work for me on windows.
Here are my editbox settings:

I know for sure that the callback is not called because I have a cc.log in the very first line of the method.

Whenever I press enter while the editbox is in focus, I only get this windows notification sound for an invalid input.

Any help for this problem?
Thanks