yeap high altitude & low idle, next time try adjust the idle by puling the idle knob & lock.
In both the 5 spd and last week with my wife's auto I set the idle up to 850 with the idle up knob. I thought it was just a NA issue, not something a turboed diesel would have issue with.
Jeff, why was your idle so low? Is it suppose to be set at 500 rpm?