X-Lite Setup

I just found the X-Lite Softphone, went through the manual and added it to sip.conf:
[16]
type=friend
secret=1234
auth=md5
nat=yes
host=dynamic
reinvite=no
canreinvite=no
qualify=1000
dtmfmode=inband
callerid="xten"
disallow=all
allow=gsm
context=softphone

yet, not matter what I put in the client, it does not register. It doesn’t even seem to try. Anyone got any ideas?

users.pandora.be/Asterisk-PBX/Softphones.htm