Congratulations with SOLR-1.2.0! The only problem is changed protocols, old client application does not understand new XML responses from server. It recalls some very old discussions related to JSON-based Java(!) client for Java(!) server (sure, RMI is the purest... Forgotten!). Same is true for Ruby and Co.
Going to Flex. We wouldn't have any problem in case of WSDL which everyone understands. Unfortunately main documentation pages do not describe new XML-based SOLR /protocol\. Thanks!