I recently bought an 55LM670T about a month ago. I connected an external 250gig hard drive to the HDD USB port. One of them 2.5 inch versions that powers from the USB Port. It has been working OK, to a point, but a problem, which I am wondering are others seeing a similar, and if not, what HDD they using. I can record a channel SD or HD. When I playback a HD recording, the playbak will always have a problem. I can be watching the playback quite normally, and I will get a 3 to 4 second black screen, no sound, and then the recording will come back alive missing the 3 or 4 seconds of image. If I replay the same recording, the blank 3 to 4 secs will be in the exact same place, so, the problem is at the recording point. This problem does not appear on SD recordings. The external hard disk I am using is a Hitachi 250gig - (type - Ts5SAA250) at 5400 rpm.. Does anybody else have a similar issue... or... Does anybody else NOT have an issue with HD playback from the HDD and if so, what drive are you using?