The facebook-friends-compare feature still doesn't work for me...only I myself show up on the list. The most recent hi-score displays just fine if you switch from "overall" to "friends" only without an acompanying leaderboard rank, but switch to "personal" and you see your ranking according to a previous much lower score.
A malfunctioning leaderboard pretty much amounts to no leaderboard. As of yet it's unfortunately a faux-feature of TPA.
It seemed to work for me before Saturday, 2/17.... Now im just getting the top 1 - 8, where it used to post my score and where i ranked. My old scores for the machines i posted on are still there... Its like weird. They just got to work it out. Same as SAS Zombie Assault i love... It took em awhile but now its good. Pray for the fix here cause i play to post.
You should try playing for fun. In the end it will be more rewarding for you.