Movie Maker Black Boarders

I use AVCHV video for input. Project is set for 16:9. While editing view window will go from full screen to 4 black boarders. If I stop at this point and perform a split the boarders disappear, I can then add a animation and the boarders will not reappear. If I remove the split the boarders return. I can edit the entire movie this wan and never see a boarder again, but when I save the movie for high definition 1920 X 1080 .wmv format for input to Windows DVD maker the black boarders are around the entire movie. This problem is with Windows Essentials 2012, I did not have this problem with Windows Essentials 2011. I have removed Windows Essentials 2012 and installed Windows Essentials 2011 but still have the same problem.