Click on the Finder, and from the Finder menu bar, choose 'GO->Utilities'. Then open up the 'Terminal' application. This will bring up the command line in OS X.
Type this in:
sudo plutil ~/Library/Preferences/*.plist
Next press Enter, and you will be asked for your password, type it in.
Now you will get output that looks like this:
If the preferences are OK, you should get an OK at the end of each line. If you get one that isn't OK, simply delete it, and the next time you start the Application, it will create a new one. You may need to re-customize the App, but it's a necessary evil.
BONUS TIP: Don't want to look through each filename for an 'OK' to see if everything is valid? Type this instead: sudo plutil -s ~/Library/Preferences/*.plist
We added a '-s' into the command, and this will suppress all output.. unless there is an error. So if you get some output, then you have a problem with the noted preference file.