Forum .LRN Q&A: Re: Which postgres release for dotlrn?
Maybe it is a bug in the development version of OpenACS that you got from CVS. If you want to install a stable version of dotlrn than go for the oacs-4-6/dotlrn-1-0 branches, as described in a comment at the bottom of http://openacs.org/projects/dotlrn/dotlrn-doc/dotlrn-installation.
Anyway, the latest 7.2.x postgresql version is recommended. 7.3 still needs some patches to work with OpenACS as you can see on other threads on this bboard.