Every once in a while my mower wont move. when i release the clutch/brake it stalls the engine. It does not matter if in reverse,neutral, or foward. Some times if i wiggle the belt and move it a little the mower will start to move a again. But this time my mower is suck in a half foot deep mud and water. The mower was moving then i shut it off to get some thing then when i came back to start it, it started but stalled when i put it in gear. This happened beffore ussually it is when the mower is parked on a hill. It is a 2005 Craftsman lt1000 with the Kholer 17hp OHV engine with hydrostatic trans-axel. Any ideas???