TMG 2010 anonymous access

Hi all,

I upgrade from ISA server 2006 to TMG 2010 . In the ISA server we using forward proxy from authenticate and nonautheticated users . But after I upgrade to TMG 2010 nonautheticated users which try use proxy , the proxy return access denied.... in the proxy is setting all users ... How I set for nonautheticated user ?

thanx

Falcon