Apple yesterday released iTunes 11.1.3 which resolves an issue where the equalizer may not work as expected.
The update also improves performance when switching views in large iTunes libraries.
In addition, iTunes 11.1.3 includes additional minor bug fixes.
The previous version of iTunes added support for OS X Mavericks, Arabic, and Hebrew.
Note: If you are using OS X Mavericks, your book library can now be found in iBooks for Mac.
iTunes 11.1.3 is available via Software Update and also via standalone installer here.