There are many hundreds of posts by users experiencing the problem in the Apple Discussion Forums,i.e.:
To address the problem Apple yesterday released Mac OS X v10.6.7 Supplemental Update for 13" MacBook Air (Late 2010) which "addresses an issue that makes the system unresponsive when using iTunes." The update is recommended for all 13" MacBook Air (Late 2010) users running Mac OS X v10.6.7.
Tip: Bill Elkus