NEED TIME STRETCHING HELP

Hey Folks,
I need help with the Time Stretch feature on the 4000. Every time I attempt to time stretch a sample, it doesn't appear to sound any different from the original. Does anyone who uses this feature have any tips that don't appear in the user manual?

I have, but when I play back the sample, it sounds the same as the original. Any pointers?

Hit the sample button > go to f3 (region) > press f4 (bpm match) > make sure the section is set to "region" then dial in the new tempo.

load a drum loop

choose amount 200%
preset perc 1a
adjust +50

and you will start getting affects like this

http://www.youtube.com/watch?v=O3-rr_oGkgc

used a lot also in drum on bass for those metallic sounding voices