While the latest version of BackupPC is 3.1.0, the latest available version in the Ubuntu repositories is 3.0.0. Normally, I wouldn’t split hairs over a point release, but 3.1.0 has some very nice, new features of which IT administrators may want to take advantage.
The problem with downloading the 3.1.0 source and manually installing it is that the source doesn’t install cleanly over the Ubuntu version and ends up breaking BackupPC. Luckily, the Debian repositories already have an unofficial 3.1.0 package in them; however, the Debian version depends on some packages not present in the Ubuntu repositories, such as www-common. So you may want to extract the contents of the Debian BackupPC 3.1.0 package and repackage them for Ubuntu, without the dependencies that Ubuntu does not have.
You can download BackupPC 3.1.0 for Ubuntu at my website.