Yes there are problems at the 1 in 30 to 50 level. I'm left right now with 135 shows on the INTERNAL disk that fail to finish their transfers in the last 0 to 6 seconds. This is from transferring 3000 to 5000 shows from EHD to IHD to EHD--called reorganization. Changing from drives with the same rating to alphabetical, which makes it easier to find the right disk--until you fill them.
Transfers should be done with the receiver newly rebooted and with minimal recordings and current viewing, just suggestions.
If a show fails earlier than 6 second left, then retry or reboot and retry. Or re-record and try.
-Ken