Dotnetpanel

some light on this error I am experiencing with the dotnetpanel Applications Installer?

I am trying to install the phpBB3 application pack on DNP2.8.5 which has worked flawlessly on my dev server, however when I run this on my live server I get the following error:
System.Web.Services.Protocols.SoapException: System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Exception: Error executing 'INSTALL_APPLICATION' task on 'phpBB3' APP_INSTALLER ---> System.Exception: Error executing 'ADD_VDIR' task on 'forum3' WEB_SITE ---> System.Web.Services.Protocols.SoapException: System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Exception: Could not get account sid ---> The Virtual Directory has been created and shows up in DNP and IIS - so why the error?

Both servers are running Server 2k3, IIS6.