Hello,
I investigated the problem putting my OpenSER in debug mode and it occurs
that the problem does not exist when OpenSER is launched with "fork=no"
instead of "fork=yes".
Though, I will try to have a closer look at my openser.cfg file and try to
set up your solution as it appears that I have a transaction problem with
the presence module as well.
Thank you very much for your help,
Antoine