Okay more slow developments. I am absolutely positive it’s not the actual images, there is nothing on them to suggest any vertical lines.
I have worked my way around this problem on most of the scenes using a series of track mattes and layering the layers in slightly odd ways.
It’s deffonately related to the track matte in some way, possibly it’s not reading the matte sequences perfectly and this is what is causing it? If the mattes are disabled, the lines disappear.
Also, each time AE is loaded, the problem lines seem to move to a different location, different length and sometimes even horizontal. All a little odd!
Cheers for your help.