Video Clips not playing back in Aperture Slideshow- Help?

Hi,

I'm trying to make a slideshow that incorporates video and photos. However, when I add photos that have been digitized through FCP from an old tape, they do not play back. Newer video clips straight from an iPhone (for example) work. This leads me to think it's a Codec problem. It was originally in the DV/DVCPRO - NTSC, Linear PCM Codec, which obviously is not fully supported (though it does playback fine in Aperture and in Quicktime, just not in Aperture slideshows). However, try as I might to convert it to other formats, the problem persists.

I've tried H.264, Linear PCM as well as H.264, AAC (converting using MPEG streamclip. Exporting from QT 7 doesn't work, oddly). One curious thing is that the audio does work in the slideshow, the video itself is just black. Very strange. These clips DO work when I try to recreate the same slideshow in iMovie, as well as a couple other cheapo slideshow-maker softwares. So I know it's not the videos themselves, but the software. iPhoto also doesn't play them. Can anyone help? I'm super frustrated that a piece of software I paid for to do just this fails to do it.

• I do not have the 3ivx Video Codec installed.
• The video is not referenced
• The Library is not on a shared folder

Thanks in advance for any insight/advice you may have. I've seen this problem before, but never with a solution.