.SWf files not showing in book?

[craftycs]

I have created seperate swf files for all the pages in my book however they do not appear when viewing the book... I did a test to see if it was the location of the files by placing a JPG image in the same location and referencing that and it appeared no problem.

This is my first ever attempt at using this software and so any help would be greatly appreciated. Do I need to specify a width and height for SWFs to show?

P.S. I checked the swf and it definitely contains content.

thanks in advance
Paul