Interesting - before getting replacement just check the voltage on the old battery, should be around 12.5v.
Mine would play dead with a brand new battery, sometimes completely dead, other times it would pop the doors but then not start - acted like a dead battery, it would even loose window memory - disconnecting and reconnecting the battery would usually bring it back to life.
Eventually found it was terminal 15 relay under the steering column gone bad, I have not had any issues since.