Datasource for Oracle

I get a telnet conection with localhost.
After installing 1.7.5 I forgot to put the ojdbc14.jar in the classpath!
But still I get an exception:
16:49:41,734 ERROR [WsdlTestCaseRunner] Exception during TestCase Execution
java.lang.Exception: Failed to prepare testStep [Check db]; java.sql.SQLException: invalid arguments in call
        at com.eviware.soapui.impl.wsdl.testcase.WsdlTestCaseRunner.run(WsdlTestCaseRunner.java:155)
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
        at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)

I've also tried with 127.0.0.1 instead of localhost, but no success.

Any idea?