Seriously - does it really matter if someone uses (CONT'D) when dialogue goes over a page? Did a memo go round saying not to do that only no one told Final Draft (which does it automatically)? I know I've only had one film made, but I've read scripts online, I've been given scripts to read by actual production companies and the fact is everyone writes differently. But in the end, it's a blueprint, it's not a finished product; it's there as a basic design for the finished product. And if someone rejects a script because you wrote (V.O.) instead of (O.S.), or your margins are 0.1pt out or you use a passive voice once in a while, then you're probably better off not getting your film made by that person. The reason people point out that stuff so much in script feedback (and I'm guilty of this too, occasionally) is that it's easy. If you know the rules it's easy to spot someone breaking them. It doesn't mean it's a bad script. And once you're in production script formatting is the least of your worries.
So use Final Draft or Celtx or something that makes things easy on you, but don't agonise over the formatting - I guarantee that if you get feedback from someone who only picks up on the formatting that person has never had a film made.
Rant over - here's an ace Nina Hagen video: