Code:
3/6/12 7:01:59.281 PM [0x0-0x19019].com.apple.iTunes: The plugin 'Quartz Composer Visualizer' failed to load because it has the wrong CPU architecture for this version of iTunes. (3585)Looking at the executable for this particular plugin (via the lipo -info Terminal command) reveals that its architecture is i386. iTunes expects x86_64... hence the failure. I wonder if Apple knows about this, and has any plans to fix it.