You have a MOSS Publishing Site, and a Survey, Anonymous access is already enables on the site (and working), But if you enables the Anonymous access for the Survey (with the all available options Add,Delete,Edit,Read ...) its still Not working, and When you navigate to the NewForm.aspx it still asks for Username and Password, solved below
http://social.msdn.microsoft.com/Forums/en-US/sharepointecm/thread/b0c812a2-ee45-4cdb-883e-ce7187d393fb
and for more info about the ViewFormPagesLockDown feature find the link below
http://technet.microsoft.com/en-us/library/cc263468.aspx#section6
and this works with the anonymous permission for DispForm.aspx for any list.
