I can call in and watch the VP screen. It shows playing the greeting. I enter in an extension, and the call is dropped. However on the screen it shows the correct box, says Pausing, Please hold, Xfer dialing. Sometimes I hear the "Please hold" before it hangs up, sometimes not - it seems to get cut off at random times.
That to me seems to indicate the call is being dropped outside the VP unit at least. Might be the phone system, might be the PRI.