Comment 6 for bug 1439476

With Gavin's help, today we looked into possibilities regarding how this might occur.

I think it's likely that dhcp_post_change_Subnet() (maasserver/models/signals/dhcp.py) is the cause of this bug.

I'm still confused about the stack traces in this bug, though. I think we need to prioritize cleaning up the stack traces we get from Twisted so that we can track these down easier...