Safari 5.0.5 won't start up?

Question

Hi there. My Safari was working fine until I did a Software Update to Safari 5.0.5. Ever since it won't load, and it crashes every time. Here's the "Problem Details" it gives me. Can anyone diagnose and help me?
Problem Details
Process:         Safari [407]
Path:            /Applications/Safari.app/Contents/MacOS/Safari
Identifier:      com.apple.Safari
Version:         ??? (???)
Build Info:      WebBrowser-75332203~3
Code Type:       PPC (Native)
Parent Process:  launchd [301]
Interval Since Last Report:          98 sec
Crashes Since Last Report:           1
Per-App Interval Since Last Report:  0 sec
Per-App Crashes Since Last Report:   1
Date/Time:       2011-07-23 14:17:25.038 -0400
OS Version:      Mac OS X 10.5.8 (9L31a)
Report Version:  6
Anonymous UUID:  8DFD776B-D586-4EAB-919E-BFA4E789D86C
Exception Type:  EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x000000008fe0105c
Crashed Thread:  0
Dyld Error Message:
  Symbol not found: __ZN3JSC15JSWrapperObject12markChildrenERNS_9MarkStackE
  Referenced from: /System/Library/Frameworks/WebKit.framework/Versions/A/Frameworks/WebCore.frame work/Versions/A/WebCore
  Expected in: /System/Library/Frameworks/JavaScriptCore.framework/Versions/A/JavaScriptCore

Answer 1

For diagnostic purposes we need a copy of the entire crash report. But in the meantime:
If your Safari won't open, one or more of the following procedures should fix it:
1.  Go to Home/Library/Safari/ folder and remove the following two files:
history.plist
lastsession.plist
(Safari may not load properly If these two files are corrupted.)
and also go to Home/Library/Preferences and delete the file com.apple.Safari.plist
2. Go to Home/Library/Caches/Metadata/Safari/ and remove the [i]contents[/i] of that folder.
(These are just  webhistory files and are not required for Safari to run. However, similar to preference files, problems can arise if they have become corrupt.)
3. Locate the cookies.plist file that's located in the Home/Library/Cookies/ folder and remove it.
(Again, faults in stored cookies may interfere with Safari's launch.)
4. Check whether any of your third-party internet plug-ins may be interfering with the launch of Safari by carefully moving them to the desktop (do NOT delete them at this stage). You can find these in two places:
Home/Library/Internet Plug-Ins/ folder, and Global plug-ins are located in the Macintosh HD/Library/Internet Plug-ins/ folder.
Also look in Library/Input Managers where other third party add-ons may lurk. If you find  a SIMBL folder, please note that some SIMBLE.bundles may require updating or possibly removal. More information on third party add-ons here:
http://support.apple.com/kb/TS3230?viewlocale=en_US
Restart Safari and place them back in the correct folders, one at a time, closing and re-opening Safari each time. If you discover that one of them was causing the problem with launching Safari, trash it and download and install a fresh copy.
Note also that Safari does not accept any third party tool bars not supplied as part of authorised extension. If you have installed any of these, delete them, or post back for instructions on how to do so.