Same issue here. There really isn't much to screenshot, it's a blank white page that just says...
"You do not have sufficient permissions to access this page."
These are the pages where this appears...
Here's my list of plugins, in case of some compatibility issue...
All in one Favicon
Automatically Paginate Posts
Basic Google Maps Placemarks
Contact Form 7
Google+ Author Information in Search Results (Free Version)
Google Analytics Dashboard for WP
NextScripts: Social Networks Auto-Poster
Rackspace Cloudfiles CDN
Simple 301 Redirects
WP Super Cache
Yet Another Related Posts Plugin
I even checked the role permissions with WP Role Manager, and it shows that I have permission to edit these two pages specifically, yet this error still appears.