Why does my Launchpad background revert to default in Mountain Lion?

Question

This is a very minor issue but it has me curious to know the reason. When I activate Launchpad I use ctl+opt+cmd+B to cycle through the background effects and choose blurred black and white instead of blurred colour. My setting never seems to stick though. It will revert back to the default setting with the blurred colour background, most likely when I restart/reboot.
I've done some searching around for this but haven't had any luck finding out the reason for why Mountain Lion won't retain this setting. Any ideas?

Answer 1

If you log in automatically, a long-standing bug will cause the desktop picture to revert to the default image at every startup. The only known workaround is to disable automatic login in the Users & Groups preference pane.
If the desktop picture always reverts to a plain blue background, one of your login items may be causing the problem. The "TeamViewer" application can have this effect; see this thread. If it's not that in your case, rule out all other third-party login items as possible causes.
If you have a MacBook Pro model with automatic graphics switching, disable it temporarily in the Energy Saverpreference pane, set the Desktop picture, then reboot and re-enable graphics switching.
If none of the above applies to you, proceed as follows.
Back up all data.
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 items to the Desktop, if they exist:
Application Support/Dock/desktoppicture.db
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.