@Bugmagnet
Yes, superseeding causes the seed to show with incomplete content
it's by design
Excerpt from Bitorrent protocols pages BEP16 :
http://bittorrent.org/beps/bep_0016.html
The super-seed feature in S-5.5 and on is a new seeding algorithm designed to help a torrent initiator with limited bandwidth "pump up" a large torrent, reducing the amount of data it needs to upload in order to spawn new seeds in the torrent.
When a seeding client enters "super-seed mode", it will not act as a standard seed,
but masquerades as a normal client with no data. As clients connect, it will then inform them that it received a piece -- a piece that was never sent, or if all pieces were already sent, is very rare. This will induce the client to attempt to download only that piece.
read the rest of the article (it's not long) and full of infos
hope it helps