asterisk users - Apr 2007 - Asterisk IAX Configuration Problem

Hello everybody,

I am quite new to asterisk. I have tried to connect two asterisk boxes
with the iax2 protocol, but although the web is full of documetation for
that, I was quite unsuccessful. 

The last try was Example 2 from
http://www.voip-info.org/wiki/index.php?page=Asterisk+-+dual+servers

I am running two machines, "gonzo", my home system and
"laptop", a
machine wit a dynamic ip address. 

The (simple) iax.conf of gonzo looks like:
[laptop]
 type=friend
 user=laptop
 secret=1234
 host=dynamic

laptop's iax.conf looks like:
[general]
 register => laptop:1234@sag.ich.net

[gonzo]
 type=friend
 user=gonzo
 secret=1234
 host=sag.ich.net

Unfortunately, the registration does not seem to work. On laptop I get:
laptop*CLI> iax2 show registry
Host                  dnsmgr  Username    Perceived             Refresh
State
84.56.146.22:4569     N       laptop      <Unregistered>             60
Timeout

On gonzo: 
gonzo*CLI> iax2 show registry
Host                  dnsmgr  Username    Perceived             Refresh
State

If I change the register => to a false login or password, I get an error
message. "No registration for peer 'laaptop' from ...", but
with the
correct data I cannot find any log entry about what goes wrong here. 

This is getting really frustrating, especiall as it seems quite simple
to configure. Does anyone have a hint for me? 

Thanks,
	Chris