Shadows (AO?) flicker during animation

I have rendered 150 frames of an animation, the first 125 frames or so appear to be fine however around frame 126 some shadows start to look different for each subsequent frame and therefore start to flicker during the animation.

I have four lights none of which have ray traced shadows also my AO is approximate with pixel cache turned on (not sure if that affects it.)

I have recalculated normals on all meshes but not sure if its that.

Can anybody help with this problem?

Cheers, Matt.

Not with so little infomation and no blend file to review.

Hard to say for now. But perhaps some things to consider.

With very small details in the models, Pixel Cache tends to give flickering in those areas. Turning it off will help.

Flickering in bigger areas (big faces) could be solved by lowering the Error.

If your lamps use shadow buffers it might all be a different issue.

Sorry for the lack of information.

I just thought that it may be a common problem with approx. AO that you guys had come across before.
I considered uploading the .blend but unfortunately I would have had to remove too many meshes for it to be small enough.

Anyway, I think I know what the problem is - four meshes had array and mirror modifiers - I’ve applied them (and reduced the error setting on approx. AO to 0.1) and so far there seems to be no flickers.

Thanks for your posts, cheers, Matt.