Instead of trying to catch every "keep all admin menus expanded" plugin, just check for the most popular one: Expanded Admin Menus. 

After some thought, it appears impossible to reliably determine if the user has one of those plugins/hacks active. This is because some of them have per-menu settings (expanded vs default behaviour), so you can't detect them by checking how many menus are expanded/closed. The previous approach led to false positives. Given that only a tiny minority of people use those plugins, it's probably okay to only look for specific ones.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@996001 b8457f37-d9ea-0310-8a92-e5e31aec5664