I have observed that my 211 DVR would lose 30-60 second chunks of recordings. I thought it was my External Hard drive, so I purchased a Western Digital My Drive (based on experiences reported in the 211 DVR thread). Unfortunately, the dropouts still occur. On the plus side, I have 25% more capacity on the new EHD.
I, too, have the "Barney" card, better know as the G3 card. I have not taken a poll to see if that is significant, but the recording errors occur on both OTA as well as satellite programming. I've even seen it happen while time-shifting. The picture will freeze and the receiver becomes unresponsive for 30-60 seconds, after which the 211 goes back to showing the program. However, when the 211 catches up to that point in time, the video will jump over that time.
I assumed it was a bad spot on the disk, or some other recording error, that caused the 211 to lock up, but it's impossible to predict. I've tried to force it by recording two events while playing one of them back, but (so far) it happens only when I don't want it to!