Are you holding down the buttons when you're binding?

Just to reiterate:
Turn the Rx on whilst holding the bind button down. Keep it down. Don't let go!

Turn the Tx on with whatever failsafe settings you're using.

Keep holding the Rx button till the light stops blinking.

I usually turn the whole lot off once more and give it a start. Not sure what procedure you use. Not being patronising.. just being thorough..