HELP! Rendering output doesn't match animation
i created an animation with cheese and ham slices being cut from a loaf by a machine. While being cut they bend down and are instantly laid down to a band-conveyor. I animated this with a lattice deformer, which looks quite good in the viewport. Punctual test renderings turned out satisfying, too.
BUT if I render the animation in the batch renderer via command line, there's a strange effect. Some of the slices don't fall down on the conveyor flatly, but stay in a position shortly before the flat one. The result is that the slices stay lifted at the foremost edge, which is anoying.
This is just one shot, but two sections are rendered with double frame rate so I can insert a slow motion. The effect appears in real time sequences, too.
I'm rendering in mental ray with final gathering, 16 bit TIFF RGBA + Z-Depth and m2dToxik renderpass.
I already tried caching the animation without success.
Would be very grateful for hints or advice. It's urgent! Thanks for your help!