Problems
Strange behavior:
Crete a new account in "System preferences" > Accounts : Click on "+"
Login to the new account.  If no problem here it is probably something in your
user Library folder.

Try an archive and reinstall.

This worked to fix a problem where multiple finger track pad gestures didn't
work on my account after I installed files from my old mac with Migration Asst.

Can't see servers on OS X 10.4
Turn off Firewall in: "System Preferences" > Sharing > Firewall

Startup problems

- Boot to "Safe Mode" (Safe Boot) by holding the shift key from chime until
you see "Safe-boot" on the progress bar box.  This disables a lot of functions
(kernel extensions) and runs a fsck in background.

-  Boot to single user mode. Hold Cmd-S at startup.  You can then run fsck or fsck -f.

-  Select System by holding optn at startup.

See Magical Macintosh Key Sequences

See:

How To Troubleshoot Your Mac



See also:

Apple Tech Exchange: images.apple.com/support/
MacFixIt troubleshooting solutions for the Macintosh:www.macfixit.com
http://www.missingmanuals.com
Mac Resource Page: www.macresource.pair.com
MacCentral Macintosh users news and forums:www.maccentral.com

How To Troubleshoot Your Mac

Restoring User Library Files 

last updated 6 Feb 2009