This is sort of a strange question and I guess I just wanted a little more clarification on it...
I have been using Slackware now for a while and have gone through several successful kernel builds using the great posts in the Slackware forum to help me out. I was assisting a co-worker today in updating the kernel on a SuSE 8.2 box from the 2.4.20 (SuSEfied) kernel to the latest stable, 2.4.25. We went through the process as it is documented here in the Slack section and all went well. I modded the GRUB settings so that I created a new entry and pointed to the correct vmlinuz version.
We then rebooted and that's when the fun started.

When I selected the new kernel, things started scrolling by like normal and then suddenly the process stopped with the line "Kernel Panic: VFS: could not mount root fs on 03:06" (or something to that degree). After doing a little research on the web, I found a post on linuxforums where it was suggested that the "initrd" file is specific to the kernel image and that a new kernel image would need a new initrd by use of "mkinitrd". So, I tried it out, altered my GRUB configuration to point to the new initrd file and VOILA! I had a successfully booting 2.4.25 kernel.
So, now to my questions:
1) Is the use of "mkinitrd" SuSE specific?
2) When I build kernels in Slack, does a new initrd automagically get created in the process?
Thanks for any help.