Once a week (every Monday morning) I do the following to repair my permissions and basically keep my system in check. You can try it as well and see if it makes a difference to your system.
1) Restart your computer holding the SHIFT key down.
2) When the blue screen appears, let go of the Shift key (notice the words, “Safe Boot” that appear on the screen)
3) When your system boots, go to Applications -> Utilities -> Disk Utility
4) Open “Disk Utility”
5) Select your boot disk 6) Run “Repair Permissions”
7) When done, restart your computer and Happy Editing.