WaPo on last year's iPad Mini with Retina, fully up to date on software
The Washington Post has a problem with the online version as viewed on an iPad Mini with Retina display (the OS, Safari, etc. all completely up to date). I am not a subscriber, or I would call them up and cancel my subscription. I was trying to read an article from 2004 (so it is conceivable, altho unlikely, that this is limited to older articles), and noticed that I could not scroll. That is, I could scroll, but when I did, it popped back to the top of the page and repainted with new ads, which was time consuming, but it did this EVERY TIME I SCROLLED. As you can imagine, this made it impossible to read anything below the first screen. It does this regardless of orientation.
This is not the webkit browser accessed through Facebook. This is starting from the regular Safari browser.
I subscribe to the Boston Globe (online only) and NYT (online only). If I were to subscribe to a third newspaper, it would almost certainly be WaPo. But that surely will not happen as long as it has this problem.
ETA: R. points out that if you use "reader view" (url line to the left, a bunch of lines representing text), the problem is gone. Also, if you scroll well below any ad being visible, the problem is gone. The problem appears to be when any part of any ad (or at least a motion ad) is visible on the screen.