mod_logxml error

Hello,

I'm trying to build a module with similar functionality as mod_logxml, so first I'm trying to get mod_logxml to work.

It is failing with the following error:

=ERROR REPORT==== 2013-10-29 15:50:39 ===
E(<0.397.0>:ejabberd_hooks:294) : {badarg,
[{mod_logxml,send_packet,3},
{ejabberd_hooks,run1,3},
{ejabberd_c2s,session_established2,2},
{p1_fsm,handle_msg,10},
{proc_lib,init_p_do_apply,3}]}
running hook: {user_send_packet, ...(Then it actually dumps the entire message to the ejabberd.log, which is useful, but not quite what I intended)

We are running ejabberd 2.1.10.

Thank you for any help.