VoIPuser becomes unreachable as peer

I'm running AsteriskWIN32 (a precompiled Windows version of Asterisk). I get registered with VoIPuser, then a few seconds later, I get:

Code:

Feb 13 04:39:49 NOTICE[4080] chan_sip.c: Peer 'voipuser' is now UNREACHABLE!  Last qualify: 0 Feb 13 04:39:56 DEBUG[4080] sched.c: Request to schedule in the past?! Feb 13 04:40:02 NOTICE[4080] chan_sip.c:    -- Registration for 'rentechie@voipuser' timed out, trying again (Attempt #1) Feb 13 04:40:02 DEBUG[4080] chan_sip.c: Stopping retransmission on '2c08ff1f4981318c593a892d497dfd4c@sip.voipuser.org' of Request 102: Match Found Feb 13 04:40:02 WARNING[4080] chan_sip.c: Probably a DNS error for registration to rentechie@voipuser, trying REGISTER again (after 20 seconds) Feb 13 04:40:09 DEBUG[4080] sched.c: Request to schedule in the past?! Feb 13 04:40:23 NOTICE[4080] chan_sip.c:    -- Registration for 'rentechie@voipuser' timed out, trying again (Attempt #2) Feb 13 04:40:23 WARNING[4080] chan_sip.c: Probably a DNS error for registration to rentechie@voipuser, trying REGISTER again (after 20 seconds) Feb 13 04:40:29 DEBUG[4080] sched.c: Request to schedule in the past?! Feb 13 04:40:43 NOTICE[4080] chan_sip.c:    -- Registration for 'rentechie@voipuser' timed out, trying again (Attempt #3) Feb 13 04:40:43 WARNING[4080] chan_sip.c: Probably a DNS error for registration to rentechie@voipuser, trying REGISTER again (after 20 seconds)

My sip.conf (minus phones and obscured for security) is:

Code:

[general] context = default  ;              Default context for incoming calls bindport = 5060  ;              UDP Port to bind to (SIP standard port is 5060) bindaddr = 0.0.0.0  ;              IP address to bind to (0.0.0.0 binds to all) srvlookup = yes  ;              Enable DNS SRV lookups on outbound calls register => rentechie:PASSWORD@voipuser/44844XXXXXXX [authentication] [voipuser] type=peer username=rentechie secret=PASSWORD host=83.143.18.16 fromuser=rentechie fromdomain=sip.voipuser.org nat=yes canreinvite=no insecure=very qualify=yes allow=all

Have I done something wrong, or this there something else I need to add?