decode the pman messages

[Gamoto]

Hi,
I am testing a generic tcp server inspired by the mochiweb_socket_server code.
The problem is around this code:

call_loop(F,S)->
	F(S).

F is never executed (I put an io:format ...).
F is defined in an other module (inspired by the mochiweb_echo code).
Could you help me to understand these messages generated by pman tool:

<0.90.0>: call  proc_lib:exit_p(error, {badfun, echo1})
<0.90.0>: call  proc_lib:make_dummy_args(1, [])
<0.90.0>: call  erlang:integer_to_list(1)
<0.90.0>: call  erlang:'++'("Argument__", "1")
<0.90.0>: call  erlang:list_to_atom("Argument__1")
<0.90.0>: call  proc_lib:make_dummy_args(0, ['Argument__1'])
<0.90.0>: call  proc_lib:crash_report(error, {badfun, echo1}, {generic, process_accept, ['Argument__1']})
<0.90.0>: call  proc_lib:my_info(error, {badfun, echo1}, {generic, process_accept, ['Argument__1']})
<0.90.0>: call  proc_lib:my_info_1(error, {badfun, echo1})

Do you see an explanation of my problem or could you suggest me where I must concentrate my efforts.
Thank you,
John