Never used ipfilter, so can't answer on your "i'd like to known if other has the same probleme" question. But i think the number of slients is the amount of clients currenty connected to (uploading/downloading/sources/upqeues), so it could perfectly be true that 8929 clients have been filtered.
Anyway, seems to be a bug on ipfiler in rc4 which stops some clients from being filtered.
I hope that helped. Greetings!