Ours does that occasionally too if my clutch work isn't perfect. The problem is the clutch. It sucks and has no feel whatsoever. When you push the pedal down you can't tell if it's engaged or not other than the pedal being all the way up or on the floor.
2012 Silver Sport S, Silver, 6 speed, soft top, 3.73s, LSD, PCG, Infiniti, deep tint windows, Pro Comp 1028 wheels, 33" Duratracs, Smittybilt bumpers and steps, KC fog lights, Mopar slush mats and fuel door.
Happiness is a belt fed weapon.