I have had the same problem with my Code radio Kitesurfer
Bought it from Modelsport a couple of months ago, firstly it just stopped, I thought it had overheated too, but nope it had just lost the binding. Went through the process to re-bind it and it was ok the next time I used it. Just tried it today again and cant get it to bind at all.
Have it boxed up and will send it back tomorrow, if its just the rx's that are the probs easier to just post that off I guess but will contact Modelsport first. Also worth having a spare if those ones at 21quid work.
Not a good start to my "new" racing career.......