It’s on the monitor too, even when you just play back using quicktime.
I’ve got round the problem by rendering it using the Media 100 codec but now i’ve got a bad video frame error (probably a slow or full drive) so I’ll have to try again i think, i’ll give those settings a go.
Unfotunately I can’t post a screen shot as the series hasn’t been aired yet but the black spot looks like an underscore and appears only on one field at a time (and i’ve only got one incidence in a 30 second clip – still a broadcast failure though)
thanks for the help
Alex.