I asked it but did not get any answer here. If you have TPS approved already, i think it is not a big issue. If you have TPS pending but have AP, then there might be some risk. My question in Avvo
http://www.avvo.com/legal-answers/travelling-in-ap-while-tps-is-pending-with-no-othe-2501787.html?answer_id=6105943#answer_6105943