Traveling on old h1b petition and visa- when a new h1b petition was approved and worker has worked based on new petition.

My h1b petition was approved in Apr-2011, The visa was stamped in 2012 after long processing however I didn't travel on this petition as the sponsor had no longer projects for me to work by the time I got my visa stamped. Another company sponsored my h1b this year for transfer in Jan-2014. I traveled on the second petition, worked ant then left USA at the end of the project in Apr-2014. Now my first sponsor has some short time project for me to work and they want me to come and work in the US for few weeks. My visa remains valid till Oct, 2014. My query is can I travel on the first petition on which my visa was stamped but I didn't travel. USCIS shows petition status as " On XYZ Date we mailed you the notice that we have approved your case".