Hi Russell, Dave, thanks for the advice and explanation.
I did use Compressor to output the image sequence in the size that I wanted but it used to be easier just using quicktime conversion.
FCP 6 did not re-size the image sequences, so was just wondering why FCP 7 does it. I understand it FCP 7 assist in converting pixel aspect ratio if I output a single image, but image sequence usually is for video work.
I did have a problem with not being able to name the image sequence to how I would want it to be named.