dbus: how to see traces from different processes

[Matthieu LAURENT]

Hi,
I am new in using dBus. I have installed an application that use dbus
and launch several processes.
New I launch the client I see its traces (fprintf(stderr), or g_print)
but I can not see the other traces of the processes that are going to be
launched.
If I launch this process before my application I see its traces in the
console where I launched it.
Is there a way to redirect traces in order to have all of them in the
same console?
Is it compulsory to launch processes before the application? (in my case
it is annoying because a process will launch several other processes)

thanks for your help
Matthieu