EditorWindow - wantsMouseMove effect?

I’d like to get notified (or have the OnGUI called) when the mouse moves over my custom EditorWindow (without buttons pressed). Therefore I set wantsMouseMove to true - but I can’t see any impact.
Is there something else to consider?

This should work, really. Can you post the code you are using?

Thanks a lot for the feedback.

Edit: need to think. but works so far. Used

Event.current.GetTypeForControl

and this seem to have caused the problem.