Okay, I lied in my last post. I said we never had any problems, but we did just a few nights ago. It might have been from operator use though (More than likely with our guys!) and that why I wanted to see if anyone else had the same problem. The quick exchange system on our Bobcat mini-excavator just stopped locking itself in one night. We use it a lot to go from the hammer back over to a bucket, and we switch out our buckets a lot depending on the job. A piece of the steel arm that catches the lock mechanisim wore out. We had to stick a piece of metal in there and it worked. SO we welded a piece of 1/4 steel to this little thumb and it works fine again after a little grinding. I was wondering if anyone else had this problem besides us. Like I said, it could just be the abuse it takes, because we do run it almost around the clock. Thanks in advance!