Did the pbx loose power? Pbx loosing power can shut down the wireless all together even after it comes back up, and u have to manually reinitialize it. I would imagine that could cause problems with the headset.
My name is David, and I have approved this message.
P.S. A message to all,if you want to get the best response to a question, please read FAQ222-2244 first. Also give the type and version of your voice mail & pbx system & preview your post to make sure it is complete & understandable.