I recently upgrade a kernel on my laptop (slackware 10.1) from 2.6.15 
to 2.6.16 (using "make oldconfig" from 2.6.15's kernel config).  I 
pulled up lilo.conf and just replaced 15 with 16 and reran lilo - no 
problems.  Now when booting though I get this fun message:

Kernel Panic - not syncing: VFS: Unable to mount root fs on 
unknown-block (3,4)

Did some googling which seems to indicate this is a problem with a bad 
root= option - but that didn't change when I changed lilo.conf so I'm 
not sure what the deal is.  I use boot=/dev/hda2 and root=/dev/hda4 
and tried typing these in as options from the boot screen - no love. 
I'm wondering if maybe I missed something in the kernel upgrade that 
could be causing this?  What's odd about this though is I cannot even 
boot using my old kernel either.

Thankfully I have a boot floppy so I can still boot and re-run lilo or 
rebuild the kernel.  Just curious if anyone had similar problems and 
has any advice.

Thanks,

Josh