Poser 7 and Poser Pro both use Python version 2.4. In previous versions the Python Tkinter keyword "col" was allowed as a short form of "column". In the new version only "column" is accepted.

Open your PY file in a text editor and serch for "col" replace with "column". Save and retry.

Python 2.4 was used by Poser 7 from the get-go, SR3 has not suddenly updated it.