Grub Error 17, how to repair?

[Andreas Schildbach]

Hello everyone!

I just did something very stupid: I re-arranged partition numbers on my 
disk (exchanged partition 2 and 3). Now, I get "Error 17" when trying to 
boot, and can't even access my partition 1 (/dev/hda1), which I did not 
expect (because it was not re-arranged).

Can you help me how repair Grub, so I can at least boot /dev/hda1 again, 
please?

I think I installed Grub to the MBR (if this is the default in the 
Breezy Installer).

My current partitioning looks like the following:

Disk /dev/hda: 60.0 GB, 60011642880 bytes
255 heads, 63 sectors/track, 7296 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot      Start         End      Blocks   Id  System
/dev/hda1               1        6747    54195246   83  Linux
/dev/hda2            6748        7139     3148740   83  Linux
/dev/hda3            7140        7296     1261102+   5  Extended
/dev/hda5            7141        7296     1253070   82  Linux swap / Solaris

I can mount my partitions from the Live-CD. Here is the excerpt from 
/boot/grub/menu.lst for my first partition:

# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hda1.
title           Ubuntu, kernel 2.6.10-5-386 (on /dev/hda1)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.10-5-386 root=/dev/hda1 ro quiet splash
initrd          /boot/initrd.img-2.6.10-5-386
savedefault
boot

How can I boot this? I tried using the Grub shell from the Live-CD, 
"root (hd0,0)" just outputs "Error 21: Selected disk does not exist". 
When booting the Live-CD and it enters Grub, this does not seem to be a 
Grub shell, so I can only enter Kernel names + parameters (the above 
kernel line), but not other commands.

Regards,

Andreas