There is a discussion section for the Canon IPF5000 Wiki under the FAQ page. This is an open invitation to post there (as well as here, of course) for questions, problems, observations, etc. You can "join", but since I have made the Wiki public I don't know if there is any difference or not. Anyone should be able to post or edit the Wiki without any kind of membership requirement.
Please put all posts on the Wiki under the FAQ page, rather than spreading them out to different pages where they will likely be missed.
Here is a direct link to the discussion section of the FAQ page:http://canonipf5000.wikispaces.com/message/list/FAQ