is this bad??

when i replaced the rear u-joint i noticed this in the shaft from the trany to the drive shaft. should i replace it? could this be causeing my vibes?

http://img.photobucket.com/albums/v226/DevilishT2003/camaro/DSC00899.jpg
http://img.photobucket.com/albums/v226/DevilishT2003/camaro/DSC00898.jpg
http://img.photobucket.com/albums/v226/DevilishT2003/camaro/DSC00897.jpg
http://img.photobucket.com/albums/v226/DevilishT2003/camaro/DSC00896.jpg