Errors after applying Security Update v1.1

[Roland Torres]

We have a PPC 2x2GHz system that won't boot up fully anymore. It's  
running OSX 10.4.9, and has suddenly (after applying the latest  
security update) begun to spew forth a torrent of error messages in  
the various log files, which are getting quite huge:

-rw-r--r--   1 root  wheel 781840174 May  3 11:14 crashreporter.log
-rw-r-----   1 root  admin  49721036 May  3 11:14 system.log
-rw-r--r--   1 root  wheel 233518213 May  3 11:14 asl.log

 From crashreporter.log:

Thu May  3 10:57:59 2007 crashreporterd[107]: error reading from  
crashdump.  errno: 9
Thu May  3 10:57:59 2007 crashreporterd[107]: crashdump[26020] exited  
due to signal 11
Thu May  3 10:57:59 2007 crashreporterd[107]: reaping /var/db/ 
crashdump/crashdump.lock
Thu May  3 10:57:59 2007 crashreporterd[107]: crashdump[26021] exited  
due to signal 11
?????????A ??k????/L??Ũ
                 ????????`??W???W???W???W???????????Ũ??Ũ???0??,? 
D" ??.\????Thu May  3 10:57:59 2007 crashreporterd[107]: reaping /var/ 
db/crashdump/loginwindow.lock
Thu May  3 10:57:59 2007 crashreporterd[107]: error writing to crashdump
Thu May  3 10:57:59 2007 crashreporterd[107]: error reading from  
crashdump.  errno: 9
Thu May  3 10:57:59 2007 crashreporterd[107]: crashdump[26023] exited  
due to signal 11
Thu May  3 10:57:59 2007 crashreporterd[107]: reaping /var/db/ 
crashdump/crashdump.lock
Thu May  3 10:57:59 2007 crashreporterd[107]: crashdump[26024] exited  
due to signal 5
Thu May  3 10:57:59 2007 crashreporterd[107]: reaping /var/db/ 
crashdump/loginwindow.lock
Thu May  3 10:57:59 2007 crashreporterd[107]: crashdump[26025] exited  
due to signal 11
Thu May  3 10:57:59 2007 crashreporterd[107]: reaping /var/db/ 
crashdump/crashdump.lock

 From system.log:

May  3 10:57:59 launchd: /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault
May  3 10:57:59 launchd: /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault
May  3 10:57:59 launchd: /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault
May  3 10:57:59 launchd: /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault
May  3 10:57:59 launchd: /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault

 From asl.log:

[Time 2007.05.03 17:57:59 UTC] [Facility launchd] [Sender launchd]  
[PID -1] [Message /System/Library/CoreServices/loginwindow.app/ 
Contents/MacOS/loginwindow port /dev/console exited abnormally:  
Segmentation fault] [Level 4] [UID -2] [GID -2]
[Time 2007.05.03 17:57:59 UTC] [Facility launchd] [Sender launchd]  
[PID -1] [Message getty repeating too quickly on port /dev/console,  
sleeping] [Level 4] [UID -2] [GID -2]

...etc.

We ran DiskWarrior on the boot drive, but there's no change. There is  
101GB free on the drive. The machine won't come up fully - I can ssh  
into it, but the login window never appears, just a gray screen with  
the spinning beach ball of death. The system is *very* busy writing  
to all of the logs.

Maybe something associated with the loginwindow program got  
corrupted? The checksum of "loginwindow" matches that of another  
system, so I guess that's not it.

Any ideas?
Thanks!
Roland