I had only one (knock on wood). I guess the last time I cleaned it out I shut the receiver box on the wire, damaging it. I didn't have any problems, though, until I was driving my Jato up and down my street one day. It had reached the end of the street and, luckily, I had it slowed down to a crawl. I lost all control of it and it slowly crawled onto the main road. It made it across safely, stopping in some grass on the other side. Just needed a new receiver.