I have noticed recently that many people using Twitter have started to send all their tweets to Facebook automatically and are not posting directly to Facebook.
This is a very bad idea, and let me explain why. When you post to Facebook using Twitter, Facebook automatically groups your posts with all other users doing the same thing, which is becoming popular. As a result, only one Twitter post is shown unless they click the "See X more posts from Twitter". See graphic above.
In addition to your post being difficult to find on Facebook, it is also annoying to post all your Twitter posts on Facebook. Facebook and Twitter have two very different purposes, and if you keep sending all of your Tweets to Facebook, users will eventually start hiding you from their wall which defeats the purpose of spreading the information you intended.
1) Use Selective Twitter, this will allow you to easily select which tweets go to Facebook.
2) Start posting to Facebook directly. This is the best option to avoid having your post buried.
3) Use a less popular service like Ping.Fm Less people use it, less grouping of posts.
One last thought, Facebook reaches far more people than Twitter, so your emphasis should be on Facebook not Twitter.
Hope this helps!