Block Access not working

[PMB1]

I am trying to block specific devices on my network. I log into the router, go to Advanced/Security/Access Control. Turn on Access Control is checked. Allow new devices to connect is selected. I select the check box next to the device I want to block and hit the "Block" button. It prompts me with "Do you really want to block selected devices" and I select "Ok". It then displays a message saying "Updating settings" and when that is done it shows me the list of devices and the device I selected to block still shows a status of "Allowed". I have tried this from multiple pc's using different browsers. The behavior is always the same. Essentially nothing happens. Has anyone seen this issue before? Any ideas how to make it work? My Firmware Version is V2.01.26. Any help would be greatly appreciated.

[FURRYe38]

Have you set up an IP address reservation for the device you trying to control first? 

Under Advanced Tab/Setup/Lan Setup. 

[PMB1]

I have not tried doing that.  Are you saying that I must have an IP reservation set up in order to block access?

[FURRYe38]

Would be helpful. Sometimes If the IP address changes, this can effect how blocking works. You want to ensure the device has the same IP address when it connects.