Well... actualy this is not total solved... HarvestCheck is only called when using the wrong tool to break a block (example: using a axe to mine diamond ore) and not when using to correct tool. I cannot find the function that is called on every block destroying...
Okay... I've changed one thing: I registered my event in preInit, init and postInit, and it worked... And now if a register it only one time, it still works...
Thanks guys!