I had the opposite thing happen to me...when I
started the car I felt hesitation, and stalled twice. The dealer compared my vehicle w/ another, and it was operating within manufacturer specifications.
They did however, find improper lubrication on the sealed bearing of my starter and replaced it.
The only thing I can say is to go to the dealer, and have them hook it up to the computer and see if they find anything there.
Good luck.