From Mahara Wiki
Released: 1 October 2008
*** THERE IS NO UPGRADE PATH TO THIS RELEASE ***
You MUST install this from scratch, upgrading from trunk or from a previous stable release is NOT supported.
This is a preview release of Mahara 1.1 Sonorus. Things will be broken! Please do not file bug reports, but we are interested to hear your feedback on the new features, through #mahara on freenode or the forums at www.mahara.org.
This release corrects bugs in 1.1.0alpha2, which failed to install from scratch and did not upgrade correctly from the previous unstable release.