When this fault is 'active', if I make an outbound call from an extension registered to my PBX, it works fine. Then, for a short period I can accept some calls. Also if I restart the system or simply restart the asterisk service using "restart amportal" over SSH, it seems to accept incoming calls for a short period.
It's almost as if asterisk isn't even listening for calls at all, and restarting/making an outbound call wakes it up for a short period.
Any ideas on what this might be?