Getting crazy with Reason midi sync... I´ve read past topics

Ok, i´ve read all the tutorials in the forums but still cant get with this. I have a g5, and mpc and a m-audio firewire 410. I´ve done all the midi conections but i dont know what am i doing. I can shoot reason with the mpc pads but if a get this i cannot here my drums (samples on mpc), neither the tick tack of the metronome. I can only hear it if i plug my headphones on the 410 headphone´s jack, I can not hear the sound through my mpc. And If i plug the headphones on the mpc i can hear the drums but not the midy (for example, a reason synth...
I cannot understand a shit, i´ve been 3 hours with this. Shit is **** my head up!!!!
Thanks

If MPC is triggering sounds from Reason, u will not be able to hear Reason sounds via MPC headphones jack.

WHY? Cause the sounds are in Reason and NOT the MPC.

MIDI doesn't do AUDIO.

MPC is just tellin Reason WHAT to play. The sound STILL comes from Reason and not the MPC.

Which is why you need a mixer for your PC's audio and your MPC's audio to blend into one... then plug your headphones in the mixer

Thanks for your help! I´m a begginer, i have it now working