Don’t receive eapol handshakes from other computers

Hello!

I am using wireshark at MacOSX with a Tenda W311M (802.11n) on a WPA2 network. I can see the traffic from my test system (like UDP), but I don't monitor any eapol hand shakes (except for my own two way handshakes that come along time to time). I can see the gratuitious arp when I connect another computer, everything as expected, but no eapol hand shakes... Of course I set the the WPA Key in wireshark.

Thanks for any help! Regards