MSAS Cube Authentication Error

[vetteheadracer]

If I use a system account as a signon for an MSAS 2012 Server, Data Source Connection works fine and all the reports return data. If I remove the signon and change the Data Source Connection to use an external namespace i.e. LDAP in our case again it tests okay and succeeds in both CQM and DQM mode.

However on running a report / query studio / report studio as soon as I try to run a report to return data I get this message:

"XQE-DS-0004

      Unable to parse the data source signon:
Error on line -1 of document : Premature end of file. Nested exception: Premature end of file."

     DetailsExpand
RSV-SRV-0042 Trace back:RSReportService.cpp(754): XQEException: CCL_CAUGHT: RSReportService::processImpl()RSReportServiceMethod.cpp(258): XQEException: CCL_RETHROW: RSReportServiceMethod::process(): asynchRun_RequestRSASyncExecutionThread.cpp(857): XQEException: RSASyncExecutionThread::checkExceptionRSASyncExecutionThread.cpp(311): XQEException: CCL_CAUGHT: RSASyncExecutionThread::runImpl(): asynchRun_RequestRSASyncExecutionThread.cpp(914): XQEException: CCL_RETHROW: RSASyncExecutionThread::processCommand(): asynchRun_RequestRSQueryMgrBasic.cpp(289): XQEException: CCL_RETHROW: RSQueryMgrBasic::executeRsapiCommandQFSSession.cpp(1181): XQEException: CCL_RETHROW: QFSSession::ProcessDoRequest()QFSSession.cpp(1179): XQEException: CCL_CAUGHT: QFSSession::ProcessDoRequest()QFSSession.cpp(1140): XQEException: CCL_RETHROW: QFSSession::ProcessDoRequest()QFSConnection.cpp(821): XQEException: CCL_RETHROW: QFSConnection::GetParametersQFSQuery.cpp(260): XQEException: CCL_RETHROW: QFSQuery::GetParametersXQEConnector.cpp(289): XQEException: CCL_THROW: XQEConnector::send

I have followed the instructions under the Developer Works document on the topic so copied the SQLJDBC41.JAR and SQLJDBC_AUTH.DLL from the x64 directory and installed them to the relevant directories under my Cognos installation i.e.

sqljdbc41.jar in both \v5dataserver and \webapps\p2pd\WEB_INF
sqljdbc_auth.dll in both \v5dataserver and \c10_64 

and also put them into a directory on the Cognos server c: drive under a directory I created called c:\\MS_AUTH. I have also updated these entries

databaseClasspath=C:\\MS_AUTH\\sqljdbc_auth.dll;C:\\MS_AUTH\\sqljdbc41.jar;
databaseJNIPath=C:\\MS_AUTH;

in my databaseDriverLocations.properties file under the \v5dataserver directory

Anyone got any bright ideas?