Obviously, this user should just cut his losses - either sell it "as-is," or just junk the unit, or complain enough to Escort that they give him a replacement.
Unfortunately, as detectors get more complex, more issues will arise. It's just another piece of electronic equipment, and as such, is prone to any of the issues which may plague any other.
These faults aren't inherent to the x50 - there's just as much on-line complaints of anything else, from the V1 (just look on RD.net, for example) to even the toaster-oven that's on your counter.
