IDT Error - SAP NW Relational Data Source

Hi All

I am on SAP BO 4.0 SP4 Patch3. I am in the Information Design Tool and trying to create a new Relational Connection. I have selected the 'SAP Java Connector (JCo)' and the wizard then gives me the following error:

Error:
[Data Federator Driver] Unexpected exception: com.crystaldecisions.thirdparty.org.omg.CORBA.UNKNOWN: null | [Data Federator Driver] Failed to connect to any of the provided 'Central Management Server' hosts.

Cause of Error
Unexpected exception: com.crystaldecisions.thirdparty.org.omg.CORBA.UNKNOWN: null

All of the servers in the CMC are shown as running and enabled.

Does anyone know which server / service should be receiving this request from the IDT and responding?

Any ideas on the cause of the problem?

Thanks

Al.