At that time, Smart Twitter was not supporting, @replies, # hashtags, and RTs. People were searching such apps, which can update your facebook status from twitter. Now its time to update your smart twitter settings, because now smart twitter supports @replies, @mentions, #hashtags, and RTs.
You have to update your settings to use this new feature. To change your settings Go to: http://apps.facebook.com/smarttwitter/settings And just tick the checkbox. Then you have done, after that all your tweets will be seen on facebook status, whether it is a reply or RT.
Smart Twitter is a Facebook apps which update facebook status from twitter. Now enjoy with smart twitter.
Note: These days, official twitter apps for facebook is not working. Many people have reported the problem to Twitter, But twitter has not solved that yet. So, its better to use smart twitter apps to update facebook status from twitter.