Changing listen channel

[franco at hotelaqua.it]

Hi all
I'm trying to change the listen channel of an objSession.

The obj works fine when I instantiate it, $logon and $listen('channel1'): $notify is fired nicely.
But then, i.e. when the end user changes, I want to change the channel as well, so I'm trying
Do objSession.$unlisten('channel1')
Do objSession.$listen('channel2').. at this point the objSession is still listening on channel1, and the only way I found  is to logoff, do again the login and listen on channel2.
Is there anything I'm doing wrong?

TIA
Franco