3CX Phone Not Connecting

X-Lite registers with my extension, but 3CX Phone on Windows wont connect.

[2015-02-13 14:51:48] VERBOSE[2211] chan_sip.c: -- Registered SIP '10' at 192.168.0.14:44298
[2015-02-13 14:51:48] NOTICE[2211] chan_sip.c: Peer '10' is now Reachable. (6ms / 2000ms)
[2015-02-13 14:51:58] VERBOSE[2211] chan_sip.c: -- Unregistered SIP '10'

I get a 407 error from 3CX sometimes.