When rendering it only renders 2/3rds of the clip. It renderis in 4:3 rather than 16:9

Hi,

When I do a render, like a "bad Tv" effect. it renders only part of the clip. It renders as though the clip is 4:3 rather than the 16;9 it is. So for the entire clip, the right third of the clip is unrendered. In other words if I stop the play head the shot will show the left 2/3rd rendered with the effect and the right 3rd un affected. When I play the clip it looks the same way too. Any ideas what is wrong. I am using final cut pro 6. The footage is 1920x1080. It was h.264 but converted to prores 422.

Any ideas?