Access denied to a share – permissions & security are correct.

This has me completely confused. Here is the setup:
I have a folder, lets call it Folder1. I share it, clear the everyone group, and give authenticated users full control. I then want to control everything with NTFS settings, so on security I go into advanced and disable inheritance, clear the control list out, and add in domain admins with full control. That works. But then I give a user group (call it Folder1Users) read access, but they come back access denied when they try to open the folder. Calculating effective permissions for member of Folder1Users shows the proper rights.

Ordinarily I would think that this meant a problem in the share permissions, but everyone has full control there. So what’s up?