I am also new to the Kubota and have a new B. I had the grapple on in the woods and was in a bit of a hole and I could not get the tractor to move. nothing happened the tires would not spin.. Then I remembered I had finished grading the road and came back down the driveway in high gear and had not put it back in middle gear. As soon as I put the tractor in Middle speed it spun the tires and walked over the dip and out. So is this the same type of deal the tractor did not bog down or anything it just would not move in high gear.