"Stream Database operator - failure (SQL Server 2005)"

Hello,

I tried to connect to my SQL Server 2005 database with the Stream Database operator. The table is quite small with 100 datasets (the original purpose was to use this operator on very large tables) . I added an integer-key RM_Index just as it said in the description.
The connection works, but i get the following "Process Failed" message:

Database error occurred: Incorrect syntac near the keyword 'AS'. The JDBC driver has thrown ...

My Process as XML:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.1.006">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.1.006" expanded="true" name="Process">
    <process expanded="true" height="564" width="332">
      <operator activated="true" class="stream_database" compatibility="5.1.006" expanded="true" height="60" name="Stream Database" width="90" x="45" y="30">
        <parameter key="connection" value="SQL_Server"/>
        <parameter key="table_name" value="tablename"/>
      </operator>
      <connect from_op="Stream Database" from_port="output" to_port="result 1"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
    </process>
  </operator>
</process>

My latest Log entry:

Jun 24, 2011 2:23:53 PM INFO: No filename given for result file, using stdout for logging results!
Jun 24, 2011 2:23:53 PM INFO: Loading initial data.
Jun 24, 2011 2:23:53 PM INFO: Process //NewLocalRepository/Stream_Test starts
Jun 24, 2011 2:23:53 PM CONFIG: Connecting to jdbc:jtds:sqlserver://localhost:1433/databasename as username.
Jun 24, 2011 2:23:53 PM INFO: Stream Database: Primary key 'RM_Index' found: creating a new mapping table 'RM_MAPPING_tablename' which maps from the RapidMiner index 'RM_INDEX' to the primary key. This might take some time...
Jun 24, 2011 2:23:53 PM SEVERE: Process failed: Database error occurred: Incorrect syntax near the keyword 'AS'.
Jun 24, 2011 2:23:53 PM SEVERE: Here:           Process[1] (Process)
           subprocess 'Main Process'
       ==>   +- Stream Database[1] (Stream Database)

I would be glad if someone could help since it concers my bachelor thesis.


Greetings,

Peter