in looking at the console log, I see that it was last run December:
Sun Dec 26 18:17:03 EST 2010
I was able to find this kbase:
http://support.apple.com/kb/HT2319?viewlocale=en_US
Mac OS X v10.6 and later information
In Mac OS X v10.6 and later, background maintenance tasks that do not run when the computer is asleep are run after it wakes from sleep mode.
*MINE is usually shut down and not in sleep, so maybe that is why it has not run*
For more advanced information, visit these developer webpages:
http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/ man8/periodic.8.html
http://developer.apple.com/mac/library/documentation/Darwin/Reference/ManPages/m an5/launchd.plist.5.html
Mac OS X v10.4 and v10.5
If your computer is shut down or in sleep at the designated times, the maintenance does not occur. In this situation, you may wish to force the maintenance tasks to run. There are two options: Use a third-party application or Terminal.
Use a third-party application
Some third-party applications may allow you to run these tasks whenever you wish. Four examples include:
Macaroni by Thomas Harrington
Mac Janitor by Brian R. Hill
CronMaster by Dan Klein
weRclean by Parental Advisory
You can search for these or other solutions at VersionTracker (
http://www.versiontracker.com/).
Use the Terminal (advanced)
Note: As mentioned above, these steps are not necessary in Mac OS X v10.6 or later.
+Open Terminal (/Applications/Utilities).+
+Type: sudo periodic daily+
+Tip: Typing "daily" runs tasks normally scheduled for a daily interval. Type "monthly" or "weekly" in place of "daily" to runs tasks scheduled for those intervals. Weekly tasks usually require a longer time to run than others.+
Press Return.
Enter your Admin password when prompted, then press Return.
Quit Terminal when the task is complete.
Additional Information
The tasks are scheduled for 03:15 to 05:30 in your computer's local time zone. This is described further in "Mac OS X: Unexplained Disk Activity Produced by 'find' Process." These tasks do not run if the computer is shut down or in sleep mode. If the tasks do not run, it is possible that certain log files (such as system.log) may become very large in Mac OS X v10.5 or earlier.
*Do you think this option to enter these commands in terminal for 10.6.6 still works?*