[esquared]

We had this problem about a week ago. Possibly the problem is that the program you downloaded was interrupted/severely broken. Symptoms include not being "stuck" in programming mode if you aren't tethered/radio modem connected, and you can press the button and send it into program mode. The RC is in a bizzare state of running but not running, where the watchdog LED (Code error) won't turn on. We resolved the issue by swapping laptops, and found we were having a problem with the serial port.

Otherwise, look for the sliver like A.A. suggested.