rename it to *.swf and then it works.
but I don't know the reason why it's that way.
Hey, thanks for that tip. It does work, however what it does is it converts it to a bitmap. It's not live vectors and text. Also, it will only give you the first page of a multipage PDF. Illustrator and Photoshop give you a dialog asking which page you want.
So right now, I open in Illustrator and then copy and paste into Flash. Flash has an Illustrator importer with options for the vector and text. It seems like a simple thing to support PDF natively.
The method I have to use takes more time because I have to manually create a back page image and when I paste I have to move it into the right place, etc.