I've begged for this before and I think it's time again.
This is a major usability problem when composing long posts on mobile devices. I am using an LG Marquee with SwiftKey keyboard, but this has happened with other phones (LG Optimus and Swype) and with dolphin browser and boat browser, so it seems to be a site related problem.
Long posts that are larger than the window size can be tricky or impossible to edit.
Most recently, I composed a long post about pumpkin pies on the LA board. After posting, I saw some auto-correct errors so I went back to fix them by tapping the edit button.
This is where the problem is. I can scroll with a finger-flick to a certain point in the post, and then suddenly the site thinks I want to scroll the web page, not my windowed text.
Any effort to force the cursor down below this point (such as by tapping the SwiftKey cursor arrows, or by tapping the end of the bottom most line in the window, causes the window to freak out and automatically scroll me backwards to a point in the post that I don't need to edit. Alternatively, the page will freak out entirely and send me bouncing back to the top of the page, to the original post.
In a nutshell, the site seems to be confusing when I want to scroll my text window, and when I want to scroll the page.
It seems that a very easy workaround would be to implement scrolling arrows so that this frustrating thing no longer occurs. It's been driving me crazy for years, and I think it's about time for a real fix.