Yes, these clients are already dropped from download and upload queues.
No, i'em always firewalled

and overhead is smaller than you explain.
My upload is always set to 60kB/s and without this modification average download is about 5-10kB/s. With modification see screenshot for 5 hours of tonight run:

Is about 2x better than without, why - i dont known.
IPFilter (ipfilter_static.dat) is known for me, but my question is what detects these clients when its sends fake data? This is seriously problem on some popular files and i have already 42 ip's of these fake senders, but some are on dynamic ip's.
Again sorry for my horrible english.