Having delved further into this it appears all is as it should be..
FYI I am using a Matrox RT.X 100 card and it does not seem as wide screen as OHC 1394 generic capture. (Which is what my original footage was)
Having made adjustments in AE using 16:9 settings and then placing in time line against unadjusted clip (both clips captured by RT.X card) all perspective is intact.
Therefore we can draw a line under this one..
Many thanks for your help
Best
Rupert