Hope this helps ..
After any update .. Repair permissions: Go to Applications/Utilities/Disk Utility and double click it. Then select your hard drive in the left panel and First Aid at the top. Then click on "Repair Permissions." It will take a few minutes.
After That:
Macaroni ... just set it and forget it.
http://www.macupdate.com/info.php/id/9633
Macaroni is a tool which handles regular maintenance for Mac OS X's Unix core. Normally these tasks run on a regular schedule, in the middle of the night. However if you don't leave your Mac on all night, they never run. Your Mac won't wake from sleep to handle this. Macaroni solves this problem. If a scheduled maintenance task is not run when it's normally scheduled, Macaroni automatically ensures that it's run at the next opportunity, whenever the Mac is on. Repairs permissions also, on a weekly basis.
Also ...
Cache Out X
http://www.macupdate.com/info.php/id/9538
Cache Out X clears out the cache entries on your machine, helping you recover valuable disk space on your machine. Set it to run at startup by placing it in your Login items in your System Preferences. Items removed include the caches in System, Users, and Library, along with the Internet Explorer download cache. Optionally clears the IE's history cache as well.