Note Duration Question

Here's the situation:
I record some samples onto a track. Lets say I want the sample to cut off a little bit shorter than its' actual length on one of the bars. So now I go to into step edit to cut the duration of that particular sample. When I do it I hear no change. If I change the property of the note to "Note off" then it will work but the rest of the sample on the track is fugged up. Why will it allow me to change the duration if it's not going to effect the note in "poly" or "mono" mode?
So what I've been doing is sampling "nothing" and then using that note to cut off the sample. Or I can copy the sample and cut it at the desired length.
Is there an easier way to do this?

record the part over in note off mode.

assign the sample to more than one pad...then change the parameters how u want.....

Thanks for your responses. Good looking out.