Hmm that link says that some key combinations are never captured and that is not really the case here, since Win + C or Win + V work fine while over the NX client window. I can copy and paste stuff on the mac. The problem only arises when switching focus between any other Windows app and the NX client and then rapidly issuing a key combination that includes the Win key. If a small delay is introduced before issuing the key combo then it works. Is that clearer now?