Communication during a presentation is obviously done by means of what you say, but another important part is your body language. Does your body language express confidence or do you express a level of terror because you are very nervous?
There are multiple things to consider to ensure your body language is enforcing your communication intentions when speaking in front of an audience.
There are no real secrets in regards to body language when presenting. Maybe you just don't have all the information.
Read tips and tricks in the book Public Speaking Excellence and learn how to control your nerves and optimize your body language for a better presentation.