Sipphone.com registration

I think the registration on my sipphone account is expiring. It works when I stop and start the asterisk server ( but not when I ‘reload’ ). But alas, after about an hour, sometimes less, it just stops working. I’m running asteriskwin32, the cygwin asterisk server on my windows gateway, so I didn’t configure any NAT, and I’m not sure if the problem is an expired registration. Here is my sip.conf:

[general]
port = 5060 ; Port to bind to
bindaddr = 0.0.0.0 ;
context = default
naxexpirey = 180
defaultexpirey = 160
register => 1747XXXXXXX:hidden@proxy01.sipphone.com/1024
;videosupport=yes

[proxy01.sipphone.com]
type=peer
secret=hidden
username=1747xxxxxxx
fromuser=1747xxxxxxx
fromdomain=proxy01.sipphone.com
host=proxy01.sipphone.com
dtmfmode=inband
reinvite=no
canreinvite=no
disallow=all
allow=ulaw
allow=alaw
;allow=g729
;allow=h263
qualify=no
insecure=very
context = sipphone;

[100]
type=peer
username=100
secret=hidden
host=dynamic
;context=home
callerid=Me <100>
disallow=all
allow=ulaw
allow=alaw
allow=gsm
;allow=h263
;allow=h263p
dtmfmode=rfc2833
canreinvite=no