X11/XQuartz problem on 10.8.2
Take a look at this page.

It suggest trying sudo ln -sf /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/ ImageIO.framework/Versions/A/Resources/libGIF.dylib /opt/local/lib/libGIF.dylib in Terminal.

(in your case; this exact command is not on the linked page)