Not sure if I'm allowed to post links from other sites on here, but this is what I found on green crack strain and it's a clone only from my underrstanding.
Happens to be one of 2 strains I have at the time. http://www.thcfarmer.com/forums/strains/report-353/
I call it the side stepper due to after I smoke some I'm no longer able to walk a straight line and it's like one step forward and two to the side :) LOL