Queueing can lead to torrents not seeding to the tracker and the
maximum amount of active torrents needs to be adjusted to cover this.

Open µtorrent, click on options, preferences then queueing.
Under max number of active torrents put a sufficiently high number that reflects
your torrent needs, ie 90 for example.
Apply and save.
This should ensure your seeding stats will be counted.
Always refer to site tracker for accurate stats and not your client though.