bad/no pad response in record?

hey all, i have searched this one up and down and can't find anything anywhere on this. i have just learned the process of loading, chopping and assigning a sample. problem is now, the pads respond horribly when recording. the samples cut out, play a moment after the pad is hit, or don't play at all. the worst of it, is that it's just random. and on top of that it has been erasing notes in overdub. for example you put eight high hat taps in a track, and then in overdub you throw a kick in at the start, that first high hat is gone.
the samples are mono, they are one shot. they are as short as they can be. i haven't messed with any settings. there's no mute on anything. i have changed the voice overlap and gotten the same problem with mono and poly. the thing is brand new and everything was going so well and now i'm at a brick wall. the best i can offer is a hip hop sample pack from prime loops dot com. thanks in advance. and again.

Make sure your samples are (Play mode) one shot and not note on.