Parallels Desktop 4.0 for Mac is designed to perform to the very high standards of performance, stability and simplicity our users expect. As such, we rigorously test the product with any updates to the Mac OS. Our testing of Mac OS X Snow Leopard (v10.6) indicated that some users may experience issues with the software build 3844. Parallels has released an update to Version 4, build 3846, which is available at http://www.parallels.com/download/desktop/
and can be downloaded for free. We encourage our customers to do so today.