error starting the gnome on login

Hi, I'm a new Linux and Ubuntu user. I installed (march 30) the new version of Ubuntu 6.10 via a CD I downloaded on the Ubuntu internet site. I have a laptop Toshiba satellite P30. The installation was successful and easy. But, when I changed the panel properties something goes wrong (I suspect it has something to do with the transparent option) . As long as I stay on the session, it's ok. But, when I reboot my computer and login a new session, it's not working. The computer seems to freeze, sometime partially, sometime totally (I must use the power button to reboot) and after a time, I'm ejected from the session and I return to the login page. When I log with the gnome failsafe session, I have this message:

"error starting the gnome setting daemon. Some things, such as themes, sounds or background settings may not work correctly. The last message was: unable to determine the address of the message bus (try 'man dbus-launch' and man dbus-daemon' for help.) Gnome will still try to restart the Setting Daemon next time you log in."

Ok, so after a lot of trying, I finally find out that it was the option of panel that is not good. So I just reinstall Ubuntu, but this time, I did not change the panel option and everything seems to be ok now. I'm a little bit afraid of changing anything about the desktop environment now..... In spite of that, Ubuntu is a wonderfull environment. I searched and read a lot on the net. Some bugs are similar to the one I encountered, but not exactly the same. I haven't found something that is the same thing to this. for example, I tried to change the hosts file et the network/interfaces as suggests by some users. It has not done any good. And anyway, I haven't read about someone who is logout of the session... I hope you can help me.

Thank you very much