There's a FAQ on http://www.blackcats-games.net/ with this statement:

Code: Select all

May I use any bittorrent client?

No. The following clients are now banned for use on blackcats


*ABC
*Azureus below 2.5.0.0
*Bitcomet
*Bitlord
*Torrentstorm
*Transmission
*Moopolice
*Rufus
*ktorrent

These clients do not report correctly to the tracker when cancelling/finishing a torrent session.
These clients do not respect the private flags of this torrent site.


Special attention to the two last phrases.
Can this issue be fixed/implemented (interrogation)

Thanks!

Márcio (With interrogation key broken )

They probably tested some old version. If you can get in touch with their admins, tell them to test the latest stable version or give them our contact (or vice versa).