I had an error installing package categories on SuSE 10.1, PostgreSQL 8.1, OpenACS 5.2.2.
I retrieved the package from repository.
The error is at line 216 of category-tree-package.sql file.
There is an extra letter "c" at the end of this line. I corrected the line 216 to "update categories" instead of "update categories c".
After that, package categories installed without errors.
Hope that help others. Ricardo Jorge