I only have a couple of numbers in this blacklist but I think it's working good for me. I had that problem of not blocking any call after having introduced certain phone numbers but it was due to the 'correct' activation. Once you've entered some numbers, be aware that 'blocking' function is actually activated: press the title 'blocklist' on screen and be sure that 'blocklist enabled' is activated. In my opinion it should better if that function shows 'enabled/disabled' but it always shows 'enabled' and with some maemo themes it cannot be clear for the user if the function (button) is activated or not.