
Yesterday, I tried to exchange my current comcast dual-dvr, the motorola DCT6412 III, at my local comcast office (Pittsburgh/Penn Hills, PA), which I think has an 80gb hard drive. It works fine, but I've had it for nearly 4 years and I want to upgrade to a newer box with a larger hard drive, e.g. 3416, mostly since we're getting a bunch more HD channels next month and the current box can only hold 15 or so hours of HD recordings.

I was informed by the comcast csr that newer boxes, which he had at least one of that I could see, do not yet work in my area and that I should check back in the fall - great.
This seems weird and inexplicable (at least to a lay person), but before calling bullsh*t, I thought I'd poke around to see someone might be able to shed some light on why this might be the case.
I'd like to give Comcast the benefit of the doubt, but Comcast, in general, has never struck me as being all that honest, so it wouldn't surprise me if this was some kind of company line of crap.
Thanks in advance for any answers provided.
Scott