I suggest you to:
Open YaST. Select the System tab and click to Boot Loader. Here you can see the list of bootable operating systems. You can try 2 things:
Click to Other button (bottom right), and in the menu select the Reread configuration from Disk. Click to Finish, reboot, and try to boot Debian lenny.
Another way is that in the same window (Boot Loader), select Debian lenny and click to Edit button. In this window into the Kernel Image field type the patch to your Debian lenny kernel.
I had a similar experience when I installed 64studio (based on Debian Etch) on my system alongside openSUSE 11 and WinXP.
First back-up your openSUSE /boot/grub/menu.lst file.
If you can access the Debian Lenny files from within openSUSE then copy and paste the relevant stanzas from the Lenny menu.lst file to the openSUSE menu.lst file. They should look something like:
Of course in your case they will say Debian Lenny rather than 64studio. I also had to delete the savedefault lines to get 64studio to boot.
If you can’t access your Lenny files from openSUSE you will need to edit your /etc/fstab file so your Lenny partition will be mounted to, for example, /media/lenny on next boot. Guide on editing fstab: Fstab - openSUSE
2 : Bad file or directory type - This error is returned if a file requested is not a regular file, but something like a symbolic link, directory, or FIFO.
I had a look around and noticed this error may also occur due to a bad partition and may require a reinstall: GRUB Error 2 - openSUSE Forums
Before considering a reinstall, could you copy and paste the original Lenny menu.lst and your current openSUSE menu.lst inside
Sorry, ignore that last link I posted. It’s probably quite unrelated to your problem. That user was trying to boot openSUSE 11.0 using an Ubuntu Gutsy GRUB menu while you are trying to use an openSUSE 10.3 GRUB menu to boot Debian Lenny.
openSUSE 11.0 formats partitions with inode size set at 256 bytes. Older versions of GRUB can only handle 128 byte inode size. That’s possibly why the Gutsy GRUB couldn’t boot the openSUSE 11.0 partition. The openSUSE 11.0 GRUB can handle both inode sizes.
If you don’t have any luck with the 10.3 GRUB it might be worth a shot installing 11.0 and seeing how that goes?