To clarify what raskin said, if you use the same kernel version,
then you will have to append a local version to the kernel. Look
in /lib/modules/ and you will see something like:
mingdao@silas:~$ ls -l /lib/modules/
drwxr-xr-x 3 root root 4096 2008-02-11 08:02 126.96.36.199/
drwxr-xr-x 3 root root 4096 2008-03-15 18:43 188.8.131.52-smp/
drwxr-xr-x 3 root root 4096 2008-03-15 17:11 184.108.40.206/
drwxr-xr-x 3 root root 4096 2008-03-15 19:18 220.127.116.11/
Those are different kernels that have their own set of modules.
Since there are two 18.104.22.168 kernel versions, you see one of
then has a local version of -smp appended to it.
I'd recommend getting the latest stable kernel source from kernel.org
and either building it yourself, or starting with the .config file
from your present working kernel as stated above. Also build your new
kernel under your users /home/<username> directory.
If you rebuilt the kernel that your OS came with, and did not append
a local version string, you have written over the modules and now you
will need to fix that.