First, don’t panic! The following tasks can take care of many Mac OS X problems. It is easiest to diagnose a problem if one can reliably make it happen, i.e by running a particular program or doing a particular thing in a program. Most of these tasks require an Administrator’s username and password the Mac.
The first step is to run the Disk Utility program found in the Utilities folder. When it is running, the start-up[ hard drive should be selected and then repair permissions chosen. When this is done the Mac should be restarted to see if the problem still exists.
Try Using a New user
Open the System Preferences found under the Apple menu and click on the Accounts icon.
Create a new user, (supplying an Administrator’s name and password.If a login name is already filled in, then just supply the password for that account.)
Log out and
Log in as the new user. See if the problem still exists. If it does not, then the most likely cause of the problem is a corrupted preference file for the application that is misbehaving.
Log back into the account having the problem and find the file in the Library:Preferences folder that contains the name of the program that is misbehaving. (It may help to use Spotlight to search for the file in the Preferences folder.)
Drag any file or folders that contain the name of the application to the trash and
Log in and see if the problem still exists.
A More Complete Disk Check
The problem may be one with the hard drive that Disk Utilities couldn’t fix. To find and fix these problems:
Restart in single user mode, hold down the “S” key as the Mac starts up. When the black screen with white text on it. and a prompt appears enter the following command
fsck -k (note that there is a space between “fsck” and the “-k” This process may take some time.
If any error are reported, even if they are “fixed” run the command again. Run it until no errors are reported, then
Continue starting up the Mac by entering the command “exit”.
Check for Malware
Yes, even the Mac can have malware infecting it. Use the latest version of a reliable anti-virus detection and removal program to check all files for malware.
Update the Program
Make sure the copy of the program is the most current version. Most programs have a built in update-checker function.