I went looking for this "Cache" file manually through the finder via the path you gave me and when I end up in the Caches folder there seems to be no "com.apple.Safari" a lot of different com.apple.... but no "com.apple.Safari" And for some reason my Safari has not crashed yet and I had it open for more than 2hours. I hope the problem is resolved if so thank you very much for you time and effort!!!!
See if this helps...
There are two libraries..
One is root denoted by /Library
The other is your Home folder ~/Library
The Tilde character represents your Home folder.
So if you go to ~/Library/Caches/com.apple.Safari
You should see the Cache.db file in the com.apple.Safari folder.
The reason behind finding that file is that the thread that shows the crash points to the cache.
Crashed Thread: 8 Dispatch queue: com.apple.CFURLCACHE_work_queue
The link below goes to an Apple page which describes Safari 5.0.6.
It has a download link.
It says it requires Leopard but I think that is only because Safari 5.1 is now recommended for Snow Leopard.