T54W with EXP 50 and WH62

[stratos]

We have (3) T54W phones with (1) EXP50 attached to each phone. There is also a WH62 headset plugged into the USB port on that back of the EXP50. Calls are being dropped sometimes when answering with the WH62 headset. This is happening on all 3 T54W phones.

If the EXP50 is disconnected and the WH62 is plugged into the USB port on that back of the T54W, no calls get dropped.

Any help would be much appreciated.