It says what you think it says: it tries to compile wp-slim-drop1.sql but cannot because the code in it is not syntactically correct.
Your response suggest that you think that content_folder__unregister_cont defined in acs-content-repository is incorrect (which is one way of reading the error message) but what I think the error means to says is that there is a problem compiling wp-slim-drop1.sql somewhere between lines 35-49 and it involves the place where content_folder__unregistered_cont is used.
The code is not in CVS so that's all that I can tell you. My guess is that the call to content_folder__unregistered_cont is incorrect. Compare with how it is called in other places where it has been ported to postgres.
Or you could post the code and maybe some more experienced porters would figure it out.
