OS x crash calls for restart, what to do?

Question

I am running 10.4.11 on my PPC G5 tower.
Recently I have had OS System crashes. The computer freezes, screen turns black and calls for a restart. Once restarted, I get the error message that the OS crashed.
I have kept track of the date and time of the most recent crashes. I have not seen a pattern of functions I'm performing.
Looking at the Console is a new adventure, and I'll pick out a few things that might be helpful.
/Library/Logs >Crash Reporter >mds.crash.log
I see many, many reports on October 16 and only that date. I was not tracking date/time until later. And I have not had multiple crashes on one day, so I don't know what that means.
Date/Time: 2009-10-16 14:16:36.137 -0700
OS Version: 10.4.11 (Build 8S165)
Report Version: 4
And then many many reports, one every 5-10 minutes until the last one:
Date/Time: 2009-10-16 15:23:20.040 -0700
OS Version: 10.4.11 (Build 8S165)
Report Version: 4
How do I get information about the more recent crashes?
Obviously, I don't understand all that I'm reading, but a few things stand out to me that might provide clues
Exception: EXCBADACCESS (0x0001)
Codes: KERNINVALIDADDRESS (0x0001) at 0xee1d6dcc
Thread 6 crashed with PPC Thread State 64:
In the logs is also ~/Library/Logs >Crash Reporter with individual software crash reports. However, from what I have read so far in other forum threads, the system crash is less likely to be a software problem.
console.log
Lots here also. This is what stood out:
Open Scanner: locationID = 0x4b320000...
ERROR: dealWithDevice: unable to open device. ret = e00002c5
ERROR: dealWithDevice: found device not matched: 0x0019
ERROR: dealWithDevice: unable to open device. ret = e00002c5
ERROR: dealWithDevice: unable to open device. ret = e00002c5
ERROR: dealWithDevice: found device not matched: 0x1707
ERROR: dealWithDevice: unable to open device. ret = e00002c5
ERROR: dealWithDevice: unable to open device. ret = e00002c5
ERROR: dealWithDevice: unable to open device. ret = e00002c5
Found device with product id 0x0462 matching locationID 0x4b320000
dealWithDevice: found 1 configurations
found interface: 0x4703
dealWithInterface: found 2 pipes
dealWithPipes: grabbing BULK IN pipe index 1, number 1
dealWithPipes: grabbing BULK OUT pipe index 2, number 2
There's LOTS of other stuff on this file. However, I now have removed the scanner. I haven't been using it recently because it crashed a lot. Perhaps this is the culprit.
On that same file, I see repetitions of the following:
2009-10-28 08:59:20.630 firefox-bin[343] * _NSAutoreleaseNoPool(): Object 0x596470 of class NSCFString autoreleased with no pool in place - just leaking
Well, that's a lot. Maybe too much. Or maybe not the most salient bits.
So, can anyone offer some assistance? Words of wisdom?
Many thanks,
Jeanie

Answer 1

You need to perform an Archive and Install, which will preserve your applications and settings but replace your OS.
How to Archive & Install:
http://docs.info.apple.com/article.html?artnum=107120
and this also:
http://support.apple.com/kb/HT2196?viewlocale=en_US
This document explains how to correctly reinstall a prior version of Mac OS X in the event that other troubleshooting does not resolve an issue:
http://docs.info.apple.com/article.html?artnum=25404
BUT: Don't install older versions of Mac OS than what came with your computer:
http://support.apple.com/kb/HT2186?viewlocale=en_US