Creating Lower Thirds in Photoshop to import into SVP 11

I created an animated lower thirds in Photoshop CS5, using PS's animation feature.

When creating the lower thirds, I have the background set to transparent, then I added my elements that I want to move into place.

I set the bitrate of the file to 32, then render the lower thirds animation in Photoshop to an MPEG-4 format.

When I bring the clip into SVP 11, the background in black. How can I render a lower-thirds animation in PS, then bring it into SVP with a transparent background?

Do I need to do something in PS, or in SVP?

Thanks for any responses.