For now, you should use "lxpanelctl exit" (or kill the panel however you
like), and then start it with "lxpanel -p Lubuntu".

Hi and thanks for reply.
I checked that the installed binary is /usr/bin/lxpanel

lxpanelctl exit
/usr/bin/lxpanel -p Lubuntu &

the panel restarts but I get the message:

~$ lxpanel: can't start plugin volume

I will try to understand with some prints why the plugin cannot be started.
tried to log with --log 5 but nothing goes to /var/log/syslog

on lubuntu 12.10 I even tried with the patched source from the repositories
(apt-get source lxpanel) which gives me 0.5.10, then compile and install but same problem
of non patched version from sourceforge.
there should be something that the debian packages does, I tried to look but didn't understand so far.