Stripes Problem and Animation Renders

Just wondering if anyone else is having this problem - stripes on some objects in the render - and if there is a cure other than moving the objects to be centred over 0,0,0?

I rendered a model in December using the then current nXt beta, it rendered beautifully for stills (but no good for animation due to the auto exposure in-built, so I used Flamingo 2 for animation renders).

I made a few small edits to the model this week and went to render again, using the current nXt, and now get vertical stripes on many, but not all, objects.

The objects are still at the same location as rendered well before (around 2000,2000,200 in metres), they aren't on map coordinates by any means (and I understand why you'd get problems with very large coordinates).

If I move the objects by -2000,-2000,-100 they render fine again, no stripes, but all the views I set up previously (and need to use again) no longer look at the model, they look at blank space. I think I can move them or set them up again but there are about 20 so it will be a bit tedious.

Anyone know why this might have happened? And if it might go back to working like it did before? (I'm a surveyor and usually work with site data, which isn't centred on 0,0,0 but more usually 1000,1000,100 to 2000,2000,200 as in this case, so having to move models about to render them isn't ideal.)

On the animation renders, I saw a post a while ago where somebody else had come up against the same problem as me (flicker when you make the rendered stills into a movie due to changes in exposure between frames) - is there likely to be a cure so I can use nXt for animations please? nXt makes beautiful images, which I can get close to with Flamingo 2, but it's slower and not 64 bit.

If anyone knows a quick and easy way to move my views by -2000,-2000,-100 so that I can render them from exactly the same viewpoint as before I'd very grateful.

Thanks,

Jonnie