Is this video corruption happening every time at the same point in the stream? Is it only when playing back HLS streams? One property that may be worth trying is cupertinoOnChunkStartResetCounter. This is set in your Application.xml file like so within the node HTTPStreamers:
If that doesn't help please look at raising a support ticket at email@example.com and include a link to zipped up copies your [install-path]/conf and [install-path]/logs/ files. A link to the stream for testing would also be beneficial. Refer to this forum post in the ticket.