Canadian Bases version 2.1 is a re-release of "Canadian Bases: Orbinauts Edition." The ONLY change in version 2.1 is to make it compatible with Orbiter 2006 (build 060504).
This is a full install, not an update patch. For the previous version of Canadian Bases: Orbinauts Edition, which is compatible with the 050216 Orbiter version and below, see http://www.orbithangar.com/searchid.php?ID=906