I don't think it has anything to do with the courses. The 375 refers to mdl_feedback_sitecourse_map=>id, and when I remove the entry from the db, the error goes away. As I continue mapping, the error comes up again (with a different row id, always the most recent mapping I've entered), so it is happening with courses I know exist. Sometimes after removing the row I am able to reenter the mapping successfully, sometimes the error comes right back when I remap.
I will try downloading the latest version of hte module again and see if that fixes the issue.