Tagadelic pulls tags from unpublished items.

Current weighted tags query pulls tags from items that are unpublished.

Easy fix, add a join on the node table and a WHERE clause that verifies the status is 1. Obvious downside is that there's now an extra join -- there may be a better workaround, but I did not research further.

Whether or not you consider this a bug is up to you, and it may be more a bug with taxonomy, but for our site, showing tags of items that are unpublished (and thus not viewable for users) doesn't make sense and adding the join fixes it quickly.