It was discovered on Jaunty. After installing grub2, it modifies the currently installed grub 0.97 menu.lst configuration file to chainload grub2 to allow one to test grub2 before committing to it as the default boot loader.
However, grub2 modifies the menu.lst entry and adds the incorrect command to select the partition to boot from to chain load grub2. It uses:
root 7cce46fe-4883-44bb-939b-58b9483f2739
and should be:
uuid 7cce46fe-4883-44bb-939b-58b9483f2739
I suspect it was originally correct before grub 0.97 has UUID support added.
To test and install grub2 correctly see here.