I have used CustomPress to create both Post types and Taxonomies associated with those Post types.
However, when editing the Taxonomy definition - Content Types, Taxonomies, click "Edit" under the taxonomy I am finding that the Labels and most of the "Show ...", Hierarchical, Rewrite settings are lost requiring me to re-enter them.
For example: I can click "Public", "Show Admin Column" and set them to "True" and the appropriate settings are showing. I click "Save Changes".
In the "Content Types, Taxonomies" screen I see that the Name is now blank. If I go in and add in the Name then the Public, Hierarchical and Rewrite settings are lost.