I checked the reviews, and some people are having trouble connecting to Box.com too. I tried it and I get an invalid server response (or something like). Checked Box.com with a couple other apps, and it is still working.
DropBox integration still seems to be ok.
I suspect the developers are scrambling to find out what went wrong, so they can tell us a fix is in the works instead of just muttering vaguely about looking into it.