First thing you want to do is turn off the stretch knob. If you want to speed up the sample, just increase the tempo. But you will then have to increase the stretch knob to make up for the gaps in sound. You would have to do the same with slowing down the tempo.
The best bet is to always start with the stretch knob off and adjust to taste after either a) increasing/decreasing the pitch or b)increasing/decreasing the tempo. Sometimes both of these options work hand in hand: i.e, if you increase the pitch, you will normally have to increase the tempo to prevent gaps in the slices.
Also, if you want to avoid all of that headache, just get Audacity and use their timestretch plugin, which increases tempo withouth changing pitch.
Don't study these folks with that hardware talk, like money grows on trees. "Almost" everything you can do with a piece of hardware you can accomplish or at least get reasonably close to using software.
PM if you have any further questions.