You cannot specify parameters for the 'standealoneinstaller'. This is only possible for setup files which are provided by the Enterprise Console or the Control Center via CID. A description of the existing parameters can be found here: http://www.sophos.com/support/knowledgebase/article/12570.html.
Instructions on this can be found here: http://www.sophos.de/support/knowledgebase/article/63184.html.
From time to time this error is "normal" and usually occurs when the configured parent itself is simultaneously performing an update of its files. Also refer to http://www.sophos.com/de-de/support/knowledgebase/66176.aspx.
Because the communication between the Enterprise Console and the Sophos client is RPC based and some more Ports are used for the communication it would be the easiest way to disable firewallblocking between the Sophos Enterprise Console and the Sophos Client