The real problem is poorly considered and expressed requirements and the resultant feature creep. This is failure of governance, not a short coming in developers. Those saying I double (or whatever) their programmers estimates need to look in mirror and recognise the failure is their own.
So no, I do not have any trouble giving accurate estimates, but then I refuse to give any until the requirements are well defined and understood by the team. I my experience this is norm now for most genuinely agile teams.