I receive this error when ping.fm is enabled. If I disable ping.fm it goes away.
It happens when I try to access a sub-page of feedwordpress plugin (top level page is ok), OR a sub-page of couponpress theme. Disable ping.fm and everything works fine.
You do not have sufficient permissions to access this page.
this is debug info:
Pagenow = admin.php
Parent = options-general.php
Hookname = settings_page_feedwordpress/posts-page
Menu = Array
Submenu = Array
Menu nopriv = Array
Submenu nopriv =
Plugin page = feedwordpress/posts-page.php
Registered pages =