hey there Producers !

i have recently started to play with nuendo and i wanted to know how loops should be done.
i'll tell what i did and you tell me what is wrong.
i hooked up LM4mk2 as a vst instrument to a new midi channel.
i drew one bar with the pencil and double clicked it.
i drew the kick every 1 bar (i think...), then i played and it sounded good for a couple of beats, then i stopped, and then it played an overloaded big kick... wtf?

how can i do it properly, is it the way you producers do it????
ot is there an easier way or better way to do it??/
thank you.
fishfish