Dyndns/dahdi problems

I have two problems with my asterisk server:
(a) When I try to register to the server with xlite(asterisk/client behind different nat) it works only when I specify the public ip address in xlite. If I put in the dyndns address, I end up with a 401 Unauthorized error. (The dydns updates ok)
(b) Whenever the pc reboots, the fxo is buggy in that I have to call the number for it to get initialised. The patch is found here issues.asterisk.org/view.php?id=14577 but I am not able to install it due to certificate errors.