[Stuarto]

Thanks for your reply, i am now happily exporting at 1024×576 to provide my client with a widescreen quicktime file. Thank you!

The blue line is about 20 pixels wide, on the right hand edge of the screen, running top to bottom.

BUT… i think i worked out what’s causing it. I can’t mask it at all and i couldnt work out why not… then i tried turning off the Magic Bullet deinterlacing effect and it disappeared entirely!
So it seems that deinterlacing the footage caused it. Anyone else having similar problems be warned. Any suggestions how to fix this?
(no rush now though… phew!)