Software update gives error

[MFiend]

I cannot use Software Update. Whenever I try to check for updates, S/U says "Error occured while checking for updates."
This is written to the Console log:
dyld: /System/Library/CoreServices/Software Update.app/Contents/Resources/SWUpdateEngine.app/Contents/MacOS/SWUpdateEngine malformed library: /System/Library/PrivateFrameworks/Installation.framework/Versions/A/Installation (no dynamic symbol table command)

I first noticed this after attempting to do the Installer update and having a kernel panic in the middle of it.
Now Software Update cannot check for updates, and Installer.app cannot launch. This is written to the Console log while trying to run Installer.app:
Launch failed with error code -2857
2001-11-13 16:45:24.379 SystemUIServer[24398] Got nil as the string argument in NSMutableString. Pass empty string instead. Will probably crash.
2001-11-13 16:45:25.485 SystemUIServer[24459] *** Assertion failure in -[NSMenuItem initWithTitle:action:keyEquivalent:], NSMenuItem.m:83
2001-11-13 16:45:25.486 SystemUIServer[24459] Exception raised during posting of notification. Ignored. exception: Invalid parameter not satisfying: aString != nil

Any help given is very much appreciated.

 

[zfisher]

I also cannot download 10.1.1 -- Using the software update, I download the entire file and at the very end I get an error message and the download quits.

I have not installed any strange software on my computer nor have I installed any non-apple released builds

Any ideas?

Zack