I made a clean installed of Ubuntu 11.10 32 bit without a problem. It came with kernel version 3.0.0.12.
I rebooted twice with no problem. After this I applied all the recommended updates from "Update Manager" including the kernel version 3.0.0.15.
After this the system doesn't start anymore in normal boot mode. After the GRUB menu the screen remains black and there are no error messages but the “GNOME Login Sound” can be heard.
I have to boot with recovery mode to use the system. I did this clean install because I had the same problem after the kernel update a few weeks ago and didn't find any solution to fix it.
My system is a Dell Latitude E5510, integrated Intel graphics, with Ubuntu 11.10 booting and running from an external USB HDD.
Thank you for the help.