July 24, 2013
We’re also having this problem.
The Screen Options pull down tab was the first place I looked, but the “All in One SEO Pack’ checkbox isn’t there to check or uncheck.
It’s as if there’s some sort of permissions issue, but we’ve checked in both admin accounts, and ‘All in One SEO Pack’ is just missing from the edit screens entirely.
Oddly, the fields are showing in the Page and Post listings, and are editable there.