Cannot change wallpaper unless I restart...

[x1a0]

Hi all,

 

I encountered a strange problem: when I tried to change the desktop background it did not take effect immediately. I have to restart my Hackintosh to see new background...

 

In system log there are:

 

 

Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: kCGErrorIllegalArgument: CGSDeviceCreate: Invalid window
Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: Failed to create window context device
Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: CGWindowContextCreate: failed to create window context delegate.
Feb 14 12:17:33 Zhangs-MacPro [0x0-0x58058].com.apple.systempreferences[1636]: Feb 14 12:17:33 Zhangs-MacPro.local System Preferences[1636] <Error>: Failed to create window context device
Feb 14 12:17:33 Zhangs-MacPro [0x0-0x58058].com.apple.systempreferences[1636]: Feb 14 12:17:33 Zhangs-MacPro.local System Preferences[1636] <Error>: CGWindowContextCreate: failed to create window context delegate.
Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: _initWithWindowNumber: error creating graphics ctxt object for ctxt:0x136c3, window:0x0
Feb 14 12:17:33 Zhangs-MacPro System Preferences[1636]: CGPixelAccessLock failed!

 

Don't know what to do... Thanks!