I have Dokuwiki running on the company intranet on a VM box running Windows 2008 Server and IIS 7. I've configured it to use AD and single-signon. It's probably also relevant to note I'm using a plugin called "Virtual Groups", which I use to assign users to groups in the ACL panel. I use this so I don't have to submit 7 forms in triplicate to the AD admins every time I need to change a user's group setup.
Here's the issue: A user who I have assigned to the "admin" group, is on Windows 7 (32-bit SP1) using IE9 and can access the Admin area, click on the ACL Mgmt link and see all the rules in place, but when he selects a group from the "Permission for" select box, he gets a message "For admins only". I am on Windows XP and using IE8, Firefox, Safari, whatever, this AJAX call works fine. I verified this is a Windows 7 + IE9 issue by remoting into a VM box with Windows 7 installed and under my ID (which is also assigned to the "admin" group) I have the same issue: I can see the Admin panel and the ACL rules but when I select a group, the result is "For admins only". I used Firefox on this same box and the AJAX call works fine-- I get the controls to update rules.
IE9 running under Windows 2008 Server also works. Even more mystifying.
My work-around for this is to remote to a VM not running Windows 7 to make ACL rule changes, so I would set the priority of this bug to "low" if I could.