Just a thought here... do you have aero bars, smiley?
Did you use them?
One of my elbows/outside of forearm gives me jib when my aeros aren't "just so" - but angling them differently by millimetres and I have no pan at all.

On a different note, if you are using your drops and didn't have them on old bike, then your weight of your upper body resting on your arms will compound any jarring or tension on your elbows.

I used to get aching in my hands as they got used to the levers/braking, and in my elbows and upper arms from the new angle I was asking my body to perform at. However, as your body "gets used" to the different demands it should begin to ease.

However, as Grog's post suggests, listen to your body and be careful it is not something like tendonitis...

Good luck