Pindo Palm Failure

In the spring of 2009 I planted two young Pindo Palms in the same AM sunny location about 15 feet apart.
We had a very cold winter here in zone 8, Aiken SC and one of the palms was dying but the other was still
thriving. In the spring of 2010 we pulled out the dead one and replaced it with a new young pindo. It is now
September and the young pindo is also dying. The other pindo is almost 4 feet tall. They got the same care
and watering. We even installed a drip system this year so they were routinely watered during the summer.
Can anyone offer a clue as to why one location has not worked?

Is the palm watered with any method other than drip (and rain)?

Could very well be something in the soil. If I were you, before I spent more $$ on plants for that one area, I'd get the soil tested.
Barb