HR20 only recording all of some shows

This was originally posted on the D* website, and ironically, I've been seeing many people getting referred here. So here it is.

Ok, I'm stumped, and apparently so is the D* support staff. I've had the HR20 now for 2 weeks, and I'm having trouble getting it to record all of some programs. The first 8 or 10 times this happened, I dismissed it as "I'm a moron and can't get it to record right." But now I'm at 18 or 20 times, and it's killing me.
This happens on different channels, and different recording types (single-run shows, series links, etc.).

I set a program to record, let's say a normal series like CSI. After it's been completely recorded (next day let's say), I pick the recorded program from the List, and begin to watch it. 3 minutes into the episode, the screen pauses, and I get a pop-up message asking me if I want to Keep or Delete this recording. Ummm...

So I checked the recording properties and it recorded for all of 3 minutes, and this show was #1 on my prioritizer list.

The same thing has happened to me on 3 different channels (CBS, TBS, and ESPN), with series shows, and single-record shows - but it doesn't happen every time - more like 50% of the time. I've checked and re-checked the recording properties, changed the time to 10 minutes early, 1 hour longer, etc., with the same result. As an example, last night's Two and a Half Men recorded for 2 minutes, from 8:58 to 9:00 (it stopped recording just as the program was starting - I had it set to start 2 minutes early), but last week, it recorded the whole episode just fine.

After spending 45 minutes on the phone with tech support, switching the sat-in cables (1-to-2 and 2-to-1), and performing a reset, I get the same problem. Oh, and I got the Ox3e update, or whatever it's called. Same problem.

This is like HR20 roulette. Will I get to see CSI this week?

Can someone PLEASE help me??!!