I am editing material that is shot in 1920x1080 60i. I set the timeline for that setting and complete the edit. I need to export the material so that it will be letterboxed in a 3x4 frame because the website I am uploading to will not play 16x9 ratio without stretching it the longway. Up until now I have been creating a second timeline once the edit is finished and dragging the original sequence into the new timeline and answering the question that is asked with 'No" do not make the timeline the same setting as the original clips. Do I need to set the new timeline to a new setting before I do this? FCP should export the new file as a .mov file that can be imported to Sorensen Squeeze and converted to a flv. file that is letterboxed, but now the exported file is not being accepted by SS. Any guidance would be appreciated.
Not sure why you are creating a new sequence for the export.
From what you have described it seems to me that the most straight forward way for you to achieve the letterboxed 4x3 playout would be to export from your original sequence using quicktime conversion and selecting a 4x3 frame size (if you are NTSC, which I assume you are due to the 60i, I believe its 654×480 - I'm in PAL-land)and then select preserve aspect ratio by letterbox and you are good to go.