You must be a local administrator on the box you install on. You must have access to the admin$ share. Windows XP must have port 80 unblocked and File and Print Sharing must be enabled.
Because both a push and pull fail, this points to you not being a local administrator on the box. For a push installation, this would typically mean the account you used to install SMP (the Application Identity credential) is not an administrator on the local box. For a pull, it means the user who logged in is not a local administrator.
A pull install bypasses the firewall specifications I listed above, so this manual pull method would be the best approach for now.