Why does the actual recording time available not match what the 622 displays? For instance I currently have about 16 hours of recorded HD programming and the "DVR Events" screen shows a little over 10 hours of HD recording time remaining. What happened to the 3+ hours? This also seems to work in reverse when I delete some programming. If I delete 3 hours worth of HD recording, the available HD recording time will only increase by maybe 2 hours and 15 minutes. I've had this 622 since June 2006. It started out with 30 hours available, but after using a substantial portion of the hard drive, which was within a couple of weeks, it has always been like this through all of the SW updates. Is this a SW related bug? There have been numerous occasions when I have been at the edge with remaining record time showing and have wondered if the missing hours would be used or some older recording would be wiped. Anybody else see this or have any explanations?