I get an excessive ";" after all tags created by the plugin, i.e. all posts which would otherwise be tagged "longtail" are tagged "longtail;". I've looked through the code and can't see anything wrong. It's not in the skin either. I'm pretty puzzled by this, as I don't think I've seen this before, when testing this plugin earlier. I'm also doubtful it could have anything to do with other plugins. Could it be a typo somewhere in the Calais service, perhaps?
For the record, I use WordPress MU, but as indicated, I don't recall this problem when using this plugin earlier.
While writing this, the ;'s disappeared from the tags. Very strange. I'm posting this still if only to keep a record, in case others meet this strange little bug.