after compiling,rebooting, fsck fails

[tripolar <tripolar@comcast.net>]

After compiling kernel, updated grub,then rebooted getting the following
error
ooops dont have it verbatim
something about fsck failed
/dev/hda6 doesnt exist or invalid

use
#mount -n -o remount,rw

I hit ctrl-d hoping it would continue to boot but no such luck, rebooted
this time booted into old kernel
Any idea why after compiling kernel it would say fsck failed and
/dev/hda6 doesnt exist or invalid?

by the way, started from scratch didnt use old .config file

thanks