hi, vvx300 on 184.108.40.20696, with C052-XD1 base station v19.50 binaural cs 500xd headset with APP-51 EHS cable.
With the above configuration and phone set to headset memory: 0 or 1 and hookswitch mode to poly EHS
Everything worked initially for a day or so and then I stopped getting audio to the ear pieces, the mic was still hot, but couldn't hear anything. If I took the slider on the bottom of the base station to C and crank the volume I can hear the audio in the ear pieces but the mute on the headset button doesn't work on C.
I have another cable on order in case the cable is bad.
The headset works perfectly with cisco 7942 with APC-43 EHS cable.