realtime no longer installs

["Thomas H. George" <xyz@spininternet.com>]

Last week I managed - with several false starts - to install the 
realtime module and for the past few days I have been able to run

   jackd --realtime -d alsa -r 44100

with no problems.   Today, working on a totally unrelated issue, I 
re-compiled a 2.6.8 bzImage without changing the security options, ran 
lilo and rebooted.  No realtime.  After several futile attempts to 
correct the problem, I did the following:

      dpkg --purge realtime-lsm-source
      cd /usr/scr
      rm -rf modules
      rm real*
      apt-get install realtime-lsm-source
      module-assistant
            Update
            Prepare (response: kernel headers available in 
/usr/src/kernel-source-2.6.8
                                           creating symlink . . .       
         Done!)
            Select (selected realtime-lsm)
           Build
           Install

after which /usr/src contained

       modules
       realtime-lsm-module-2.6.8_0.1.1-6+custom.1.0_i386.deb
       realtime-lsm.tar.bzip2

and, after updatedb, locate realtime.ko found

       /lib/modules/2.6.8/extra/realtime.ko

but

       /etc/init.d/realtime restart

reported

       Loading Realtime Linux Security Module: not found

and modprobe realtime exited with the statement

       FATAL: Error inserting realtime 
(/lib/modules/2.6.8/extra/realtime.ko): Invalid Argument.

Next I went to /usr/src/modules/realtime-lsm, edited Makefile to set 
KERNEL_DIR    := /usr/src/kernel-source-2.6.8 rerun make and make 
install.  After this modprobe realtime results in the same error message.

Where have I gone wrong?

Tom George