ok, first, rtfm. then hit the "sample" button, followed by the "edit" button. then hit the "group down" button next to the select/ data wheel exactly 5 times. there you will be presented by a screen that says loop type. turn the data wheel counter clockwise to select whether you want it to loop in the release of the key (think asdr amp envelope) or whether you want it to loop until you release the key, at which point it will stop abruptly.
-if you have a stereo sample (aka separate samples per channal), make sure you edit both of them, and make sure in your "single" perameters, if L is zone 1 and R is zone 2, you page down 4 times from the zone 2 assign screen and adjust the velocity so that pressing your key plays both samples. Vlow-0, Vhigh-127.
-*one thing that could have gone wrong is if you were editing the loop point of sample -R and not -L, assigned-L to zone 1 and -R to zone 2, but -R wasn't playing because the Vhigh wasn't set for 127.
_check your loop time. it should say hold. if not, start at the left and make each digent a 9. @9998, if you advance the rightmost diget one more time, it will switch to "hold." this menu is 3 pages down from the loop type screen, and is called "loop time."
** - if you want the sample to loop without holding the key down, there's no option, but luckely there's a trick. hold the key to start the loop, then pull the midi cable out while still holding the key. release the key and it will stay looping. now reconnect the midi cable, and the sample will continue looping until you press the key again, effectively bullshitting a loop -> retrigger function.
This looks like a psychotropic reaction. No wonder it's so popular...