iMovie Video's Scrolling Ticker not working correctly in iPhoto

Hi...I create news broadcasts for my highschool I work at. I create these on iMovie and then they are uploaded to YouTube and played on our LCD TV's at school through iPhoto. Everything seems to be working fine these past monthes and then all of the sudden the Scrolling ticker I use gradually goes down until it dissapears. This is only on the TV's (Again, through iPhoto). This is not the case if you view the video on YOUTUBE, on quicktime, or if you go back into iMovie. Can anyone tell me a setting that might cure this in iPhoto?

Thanks!