ToCC plug-in fix: keep this assigned to Uncategorized!!!
Because of changes we made to the Table of Contents Creator code, the category Uncategorized needs at least one post to prevent it from showing up in lists generated by the plug-in. This seems to happen regardless how you configure output options found in the ToCC control panel or what code is used within a page/post to override the control panel and create a customized instance.
Keeping a published, public post (like this) in Uncategorized seems to solve this issue.