Ok, we've tried the files here and they don't play natively on the BDP (although they should, as per the device profile). I suspect it's because of some data that the DVR adds to the file and BDP's player cannot process.

You can force transcoding of those files (and all others) by going to the Advanced tab on the Device Settings dialog (from the Media Devices) and setting "Deliver media files support by device" to "Never Deliver" (leave the rest as-is). That should make all files transcode and those files should play fine then (they do here).