I had this same problem at trackside during the tcs race last year. [Mini class w/ silver can] After asking around a guy refferred me to a guy that worked at horizon hobby that was also at this race, [Garyk I think] and he looked at my setup, I also had the antenna wire looped on top of the sr3000 receiver. He advised me to get it up in the air, plus he changed my antenna on the module. There is an updated longer [ internally] antenna that some modules need. It hasn't happened since. Hope this helps.
Larry.