

The SHA256 checksums should be favored as the MD5 algorithm must be treated as insecure!

You might want to compare the checksums to verify the integrity of downloaded packages.

To install VirtualBox anyway you need to setup a 64-bit chroot environment. Debian/Lenny ships an AMD64 kernel with 32-bit packages) are not supported. Note: The package architecture has to match the Linux kernel architecture, that is, if you are running a 64-bit kernel, install the appropriate AMD64 package (it does not matter if you have an Intel or an AMD CPU).
