Left Nav links are disabled on "User Management", "User Roles", and "Appearance" pages with Internet Explorer

Steps to replicate:
1. Login as an Administrator.
2. Click on the User Management link on the left nav.
3. After the page loads, click on any of the left nav links.

Actual Result in IE7:

• all links are disabled

Actual Result in IE8:

• User Management, User Roles and Appearance links are disabled

Expected Result:

• Links should not be disabled and should work when clicked.

Tested this in IE9 and it works fine.