The shorthaul leg of my flight (2hrs) is operated by Air Nostrum..hope it isnt too bad.

The fare information on itins searched at http://www.iberia.com/ gave a 10kg weight limit for carry ons, a bit small (but better than LH).

Do they check weights of carry on at the airport?
I dont plan on carrying big luggage pieces as carry on, but my laptop bag with its 17" laptop + battery charger itself weighs 7 kgs..doesnt leave much weight for the main bag.