Ogre, when I was in a position to hire, I put "no calls, please" on the job ads because I didn't want to be bombarded with 100 calls from people asking if their stuff got to me when I had other things to worry about, like fighting about my travel budget or putting the section together.
Drop a quick e-mail. The SE can get back to you at his convenience. Nothing worse than calling an SE catching him at a really, really bad time, especially when it says "no calls" on the ad. In fact, you very well could knock yourself out of the running because you don't know how to follow directions.