/dev/psaux deleted; mknod helps but not permanent

["harley_frog@yahoo.com" <eric.speas@gmail.com>]

 am running Sarge on my wife's computer and everything installed and
ran fine from the CD install, including X and kdm.  Over the weekend, I
updated all the packages, installed them and shutdown the computer.
Yesterday, when I booted the computer, X failed to start.  The error
log said that /dev/psaux and /dev/input/mice where missing.  I tried
running

    MAKEDEV busmice

but the device files were not created.  After reviewing my Linux books,
man pages, and my trusty Knoppix CD, I figured that mknod was my best
option.  So I typed in the following commands:

     mknod -m 644 /dev/psaux c 10 1
     mknod -m 660 /dev/input/mice c 13 63

I was then able to run kdm and X without problems.  However, once I
rebooted the computer, the device files I created where gone again.  I
tried putting the abobe mknod commands into a shell script and into my
init.d and rc.n directories.  While the device files were created, I
still have to log into the console terminal and manually start kdm and
X.  This is the first time something like this has happened to me using
Linux and given my limited knowledge about creating device files, I am
limited to two options: 1) plead for help (which I am doing here) or 2)
reinstall Sarge (which I hope I do not have to do).  I am running the
Linux kernel 2.6.7 and it is not a rebuilt or new kernel.

My question is this: is there a way to make the manually created device
files using the aforementioned commands permanent (ie. still be there
after a shutdown/reboot) or am I totally screwed and need to reinstall
Sarge?

TIA