Well, IMHO, the correct description of how the Dish DVR's work is this:
1.When viewing a recording on the FOREGROUND tuner (not PIP on other models) that tuner does not buffer while you are watching that recorded program.
2.If watching a recording in progress behind real time, the FOREGROUND tuner will not buffer until the playback manually or automatically ends and the FOREGROUND screen resumes display of that FOREGROUND tuner.
3.If the BACKGROUND tuner--not the one you are watching live nor the one you are viewing your recorded program--is recording a program, then when that live recording ends, the BACKGROUND tuner will buffer starting at the conclusion of the live recording.
The key is the FOREGROUND tuner experience will not buffer--but the background will--when it is in use for playback of recordings.
This has always been the case for all Dish 2 tuner DVR's.
What you want is what TiVo does. However, TiVo Series 3 ALWAYS records on both tuners at ALL TIMES, even in standby. Kind of nice, but not really a killer "app" feature nor is it a deal breaker against Dish or any other DVR maker in the market.
Suggestion/workaround: Just before you view your playback of a recording, press the RECORD button and select Manually Stop Recording option. It will buffer the FOREGROUND tuner until you manually stop it with only your disk space remaining as its limitation.
Is this that big a deal that the workaround above won't help in your feeling satisfied? As someone who has a TiVo Series 3 that buffers at all times--but only to the limit of 30 minutes buffer time, this really isn't such function to crow about. Yeah, it was handy a few times, but not a desired feature I would ever care to have on any DVR. Very easy to press RECORD and select Manually Stop Recording option for the same effect on Dish DVR's, but even better as the Dish DVR will record for as long as you have room on the disk (hours?) or manually stop it.
So, if such a feature were that important to me, I would have to set-up the TiVo do the same thing as the Dish DVR, but it is a more cumbersome task on the TiVo as you have to navigate the cumbersome menus, then you have to select the specific start time and specific end time in five minute increments, not with precision as with Dish DVR's (date, and channel on TiVo reflect current)--must I calculate it? I want it easy like on Dish DVR's-- when what I really want is for the TiVo to record until I press stop. That means, ironically, the Dish DVR has a better manual buffer option than TiVo, and I would prefer Dish's options to TiVo's if such a feature were important to me.