GRUB Error 21

Heyho!
My Scenario:
Since the hardware of a PC made in 1997 doesn’t like me, I just installed LXDE by pluging the P-ATA drive into my current PC (with my 2 S-ATA drives being plugged in). Not worked first time, probably because I pushed the drive too hard into the old PC … Formatted again, installed LXDE again (this time my S-ATA drives plugged out). Works fine with the old PC, but when I try booting from my current PC now it says: “Grub loading stage 1.5 … Grub Error 21”. No menu, nothing … And because I plugged my S-ATA drives out, when installing LXDE the second time, the config file, grub is probably searching for on the P-ATA drive, is somewhere in nowhere …

Googled it 2 hours … Yast2 Bootloader and grub-install are just trolling me …

My PCs specs:
2 S-ATA hard-drives:
250 GB drive with Suse 11.4 and KDE 4.7 (x86_64)
sda1 2 GB (or so) swap
sda2 248 GB ext4

1 TB S-ATA drive with Windoze 7 (x86_64)
One big partition

The drive I installed LXDE (32-bit) on, is an old P-ATA, with first 30 GB, then suddenly 80 GB (don’t ask, I don’t know either) …
First formatting was 500 MB swap and the rest Ext4
Second formatting was 1011 MB swap and the rest Ext4

If the rest is relevant …

MoBo: Asus P5QL PRO
CPU: Intel Q6600 Quad@2,4 GHz
2 DVD Drives
Nvidia 450 GTS by Gainward

Be aware that when you mix SATA and IDE hard drives, the devices names (sda, sdb, sdc, etc) might change randomly - even between the setup and the next boot. This can become extremely confusing when you don’t know what’s going on. Therefore you should never use device names anywhere (Grub menu, /etc/fstab) nor trust them.

Okay, I fixed it … More or less … Just installed a new KDE on a 20 GB Partition, this generated a new Grub, from this grub i can go into my old grub and can boot from this … now just set it to autoboot … though thanks for the help