GPP issue when using Proxy Override for IE10

I am trying to use Group Policy Preferences to set the proxy server address, port and proxy exceptions for computers that have IE10 installed.

If I try to create a GPP for IE10 (from a Windows 8 computer, Windows 2008 R2 DCs) and just choose the proxy server address and port number, it works.

if I choose to bypass proxy server for local address, go into advance and add anything to the exception list, it will grey out the proxy server address and port that I had previously filled out and it will no longer work.

not sure if this matters but when I tried the GPP for IE 8/9 and did this, it worked fine. Only the GPP for IE10 seems to be not working.

Heath