User blog comment:Carwyn the Hollie Lover/Help?/@comment-4018164-20140804094024

Make sure that: In addition, if you're using an image editor for cropping, for instance, make sure not to open it with MS Paint, as what it normally does it to set a white bg. If you have no suitable image editor, you could download GIMP or Paint.NET.
 * The "transparent" checkbox is checked, otherwise it would not add an alpha channel and what you are left with is an image with a bg.
 * There are no colored parts of the swf files below the part that you want. If there are any, delete them (can be easily done using SwfModify or JPEXS).