One of the things in Ubuntu that has always driven me crazy is the addition of new items into the grub menu without removing the old entries that likely don't even work anymore. I'm sure most experienced Ubuntu users already know how to do this, but here's the method anyway.

Important: If you're using a newer version of Ubuntu with grub 2 (like Ubuntu 9.10 or later), you'll need to read about how to clean up the New boot menu instead.

I just installed this box recently, and then did an upgrade.... already there are 7 items in the menu. To remove these entries, we'll need to edit the file /boot/grub/menu.lst. You can do this by using Alt+F2 and then typing in the following command:

gksu gedit /boot/grub/menu.lst

Now that we've got the file open, scroll down to the bottom of the file where it says "End Default Options", and you'll find all the menu entries for the various kernels in here. You can just select and delete the ones you don't want.

Save the file, and then the next time you boot up you'll see a much nicer set of options.

I'm guessing it would also be prudent to clean up the other unused kernel files that are sitting out there... I'm sure there's some automated tool to do that, but I've not taken the time to figure it out yet.