This is still a problem Dish needs to fix. The DVR's will, in some instances, record old shows even if the timer is set to "New Episodes" even if the info clearly shows the air date as being in the past. This even happens on show that repeat the same day three hours later.
On a past tech forum, Dish admitted, when asked by a caller, that they did in fact open up the timers to records some repeat episodes even if you had set the timer for "New Episodes." They said that there were a lot of people claiming that there DVR's were not recording the New Episodes causing the customers to miss their favorite shows. So, Dan said, they decided to err on the side of "repeat" safety, and open up the timers to record repeat broadcasts that way customers were certain to record the new episode, and if people like you or me keep getting old one recorded to, well, that inconvenience of having to delete an unwanted recording was better than possibly missing a new episode of your favorite TV show. I think it has been over a years since they have been doing this.
It won't happen in all instances, but some instances. For example, the DVR insists on recording every instance of MTV programming that as been set for "New Episodes." And History channel programs will sometime record properly for New Episode and record only that one instance, while other shows on History will record the New Episode, and the repeat of that episode 3 hours later, and again 4 days later, and all with the correct and proper air date on them for the DVR to use.
This is a pain. Dish, get with it, and fix this!