im not really sure what you're saying, but from what i understand, you want to loop the sound continusouly? or get rid of the silence thats in the remainder of the one bar? well, ez, just take the rendered .wav in a Wave editor(FL has one i think, i dont use it tho so i dont know anything about it) and then just delete the unwanted tail end/silence in your sample.

hope that helps, but maybe i missed the point of ur question

holy crap you learn something new every day

for anyone that hasnt ever used this (like me) just press control+e in the channel settings tab

cheers

File > Eport > then when you get to the settings menue, go to the looping mode and choose "Cut Remainder"

Justin