The "Thai Binh_xar_files" is a cache folder which is a result of exporting your project to HTML, it contains a copy of any imported .swf file (added via a placeholder).

When you create a new animation in Xtreme you are using an animation template rather than a drawing template. This template changes the application mode slightly and gives you various other tools plus a frame gallery.
Once your animation is completed and you export it to .swf (File>>Export animation), you should have additionally saved the project file as a .xar. If you don't, and ignored the Xara prompt to do so, your animation project is gone save for the previously exported .swf.

I'm moving this thread as it should be in the Talk Web>>Xara Flash forum