When you say you throw the movie to timeline is this a movie you have from another source or is it one you made of your monitor/screen using the Camtasia 9 recorder ? If you could give more information as to where or what kind of movie as you called it that you are trying to throw onto your timeline or provide a screenshot please it would help.
The way it usually works is by default when done recording your screen then the Camtasia 9 Editor opens up and has your video in the Mediabin and adds it to the timeline. Then you can do all of your editing and then save the project or Share/Produce it and also Export it as a ZIP File. So, please give more information as it will make it easier to help figure out what is going on and like I said before try to post a small video or screenshot for us to see and give more detail on the steps and what you are trying to add (Throw) onto your timeline.
Sorry for you inconvenience and thanks for posting and hope to hear back from you. Have a great day/night.