When trying to upgrade Plesk 9.5.4 to 10.1.1 I found that I had to install SiteBuilder. Unchecking SiteBuilder in the autoinstaller said that the Plesk base packages require SiteBuilder. If this is really the case I don't understand why SiteBuilder has its own checkbox. But it would be even better if SiteBuilder was not required for the Plesk base packages, as we don't intend to offer SiteBuilder.