For everyone running Crunchbang Linux 8.04.01, to get the latest VirtualBox (1.6) running you will need to upgrade to the latest kernel Ubuntu provided for official Hardy release: 2.6.24-16-generic! The problem is that after installing the VirtualBox package from Sun’s website, it requires linux-headers for the current installed version on your OS, which are obsolete now and not anymore provided through repositories. The solution is to upgrade to the latest kernel (2.6.24-16-generic) which is actually the latest official for Hardy. A complete walk through can be found on Crunchbang’s forums.