Replying to What is this grey line?

Alright It's time I figure out what's going on. Almost every video I make has this weird grey line on the very bottom of the frame, sometimes it breaks up and the pieces move around, sometimes it's just a solid line and every once and a while it disappears for a few seconds. Here's an example (Watch it in full screen or you won't notice it):




This is my workflow, I'm shooting with a 60d.

- Conform footage to prores422 with MPEG Streamclip
- Import into Final Cut Pro 7
- Cut
- Color Correct
- Apply 2.35:1 or 1.85:1 matte and adjust footage to compose in the best way possible
- Color Grade
- Send to Compressor
- Compress using one of the internet streaming compression presets I've created.

Now somewhere in between the time it's in final cut and the time that it comes out of compressor that line appears. It's distracting and I need to find out how to stop it. Does anyone have any ideas? Places you recommend I seek help?

Thanks,

-Max