Thunderbird (only) cannot connect after system upgrading to Jaunty.

[Charly Avital]

After upgrading from 8.10 to 9.04 RC, Thunderbird 2.0.11 cannot connect
either to download nor to send traffic. Network connection is
functioning correctly: update-manager, web browser, Evolution.
I have not changed a thing to Thunderbird's settings, I have checked
them and found them to be correct.

I am running Linux under VMware 2.0.4, MacOSX 10.5.6. 
I shall post to the Thunderbird's list, and in the meantime TIA for any
tip.
Charly