Trying to boot Suse Linux from drive caddy on T41 notebook

Hi - I'm experienced with computers but new to Linux. I have an IBM T41 notebook. I have suse 9.1 installed on a second drive which when swapped out with drive in the notebook boots fine. I don't want to keep doing this. Its a work pc!
I also have a cd "drive caddy" - if you don't know, its a cd drive type shell that you place a hard drive in and use it in place of the cd. Very handy. So I'm trying to get the linux drive to boot off this. I select it as a boot device , boot process starts then I get this:
Kernel panic: VFS: Unable to mount root fs on hd3
Cannot open root device hda3. Then something about advice to append new boot device to the loader? Any ideas how to fix?
How does one modify the boot script? loader etc? Thanks.

Linux is known to have issues with Removable devices..

Is this the hdd you're trying to boot from the only hdd in the box?

Also, have you set up the boot loader to boot off the MBR?

The setup is this. T41 notebook pc. 40gb drive with xp only. I have a second 12gb drive which temporarily used in place of the 40gb drive and I installed Suse 9.1 on it. It booted up great all cool. But I have to continually swap out 40gb drive with the 12gb linux drive if i am to use linux. Ok so I also have a drive caddy that fits in the cd rom bay. It holds the 12gb drive and others like it. Commonly used to read problem drives etc while booted up from the main drive. I had the idea to use it to boot the linux 12 gb drive so I don't have to swap out the 40gb. The notebook has the option ( f12 for those familiar with ibm nb) at boot up to choose to boot from different source. So why not boot off the caddy drive containing the linux install.
Soory for long post -! I guess I've made this difficult! So now I guess grub is confused and can't find the boot partition? I'm thinkin I may just need to edit the grub config file. But am not sure how. To make matters worse, when I installed suse , there was already a 7gb ntfs partition there with nt and linux found it fine and now I have a multi boot with linux or windows. I don't care about the windows partition. So I opened yast and deleted the ntfs partition, hoping I could resize the smaller linux partition BUT I don't see the empty space to resize the linux partition into.?