garbled render element png`s

hi,
i`m getting garbled png render elements, vrayvelocity and vrayzdepth using png`s. deleting and re-adding the elements seems to solve it until they go wrong again at some point.
only seems to have happened in this one project (that i know of) and only recently after rendering sequences that worked fine the first couple of times.
max 2016, vray 3.40.03, also tested 3dsmax2017 and vray 3.50.04 same issue.

thanks
anthonyh

Could you give more information regarding the render elements. How do they appear to be wrong(screenshots would be helpful).

It would be best if you could send us a test scene at support@chaosgroup.com so we could reproduce the your issue in our environment.

sorry, attached…
thanks
anthonyh