Just to followup my last note.
With OpenACS 5.1.* you are asking for trouble on the long range. OpenACS 5.2 did some significant changes on the datamodel (on acs_objects), OpenACS 5.3 was putting emphasis on code quality (acs-core). Alone between the release of 5.2.3 (the version running on openacs.org) and 5.3.0 there were over 350 changes (mostly fixes) for acs-core. We moved our main platform of the university from 5.1 to 5.2 and recently to 5.3, which is intensively different from the cvs version. You should really consider upgrading.
I often get questions from people not experienced in cvs, how the get xotcl-core or xowiki from cvs head. Once you have CVS installed on your system (most linuxes have this), use the following commands to get the newest version of xotcl-core and xowiki from cvs (the newest version is called the head version):
export CVSROOT=:pserver:mailto:anonymous@cvs.openacs.org:/cvsroot
cvs login
cvs co xowiki xotcl-core
best regards
-gustaf neumann
