I found a post on the Ubuntu forums: http://ubuntuforums.org/showthread.php?t=767449
The solution for me is on page 8, in a post from "michael_nz". Simply add 'all_generic_ide' to the kernel line in grub's menu.lst. Here is the short version:
Open /boot/grub/menu.lst with your favorite editor. You'll need to use sudo.
Scroll down to your default boot section, it will have lines starting with 'title', 'root', 'kernel', and 'initrd'.
Add 'all_generic_ide' to the end of the kernel line.
Save and reboot.