sceen saver preference frozen

Quit System Preferences if it's running. In the Finder, hold down the option key and select Go ▹ Library from the menu bar. From the Library folder, delete the following item, if it exists:

Caches/com.apple.systempreferences

and move the following item to the Desktop:

Preferences/com.apple.desktop.plist

Launch System Preferences and test. If you still have the issue, put the item on the Desktop back where it came from and post again. Otherwise, delete the item.

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ If you’re running Mac OS X 10.7 or later, open LaunchPad. Click Utilities, then Console in the page that opens.

Step 1

Enter the name of the crashed application or process in the Filter text field. Post the messages from the time of the last crash, if any — the text, please, not a screenshot.

Important: Some private information, such as your name, may appear in the log. Edit it out by search-and-replace in a text editor before posting.

Step 2

Still in the Console window, look under User Diagnostic Reportsfor crash reports related to the process. The report name starts with the name of the crashed process, and ends with ".crash". Select the most recent report and post the contents — again, the text, not a screenshot. For privacy’s sake, I suggest that, before posting, you edit out the “Anonymous UUID,” a long string of letters, numbers, and dashes in the header of the report, if it’s present (it may not be.) Pleasedon’t post shutdownStall or hang logs — they're very long and not helpful.