Phones Disconnecting Inbound Calls

On an Eyebeam and X-Lite soft phone, when it is offline (disconnected) the inbound dial to an extension just disconnects the call (i.e. I exit my phone (it’s offline) and I dial that extension inbound, it completely disconnects the call after about 5 seconds).

I haven’t seen this before but I would assume it would give a message or a busy signal.

I am running Trixbox (asterisk) 2.2.1 with an IAX trunk.

Does anyone have any idea why this might happen or can someone shed some light on this?