Environment: Package Server with Windows 2003* SP1 server.
When building a new package server, permissions were set up to allow anonymous access to the Altiris and Package Server (PS) access. The anonymous access permission was granted using an account other that the default IUSER_Machine account. Under Authenticated Access, Integrated Windows Authentication is checked. By default, this account was the Altiris Application Identity; however, it could also be the Agent Connectivity Credential, if specified appropriately.
Open up the Internet Information Services (IIS) mmc snapin. Under Web Service Extensions, ensure that both Active Server Pages and ASP.NET v1.1.4322 are set to "allowed". If you need to make changes, run "iisreset" from the run location.