Respondus 4.0 does not officially support publishing/retrieval for Ultra courses. Once Blackboard fully develops the necessary APIs and web services, they hope to offer compatibility.
Here are some steps to manually publish files from Respondus 4.0 to Blackboard. This may work fine for your ultra courses, but if it doesn't then there isn't much we can do since it is not currently supported.
1. Open Respondus and change to the "Blackboard" personality.
2. Open the Respondus file and allow for any conversions.
3. Go to Respondus->Preview & Publish->Publish->Publish Wizard->"Save pool to local file for manual uploading".
4. Specify a file and select "Pool - no points"
5. Save the file.
6. Log into the Blackboard Ultra course.
7. In the Course Content page, select Manage banks in the Details & Actions panel
8. Click the "+" in the upper right side.
9. In the "Open File" window, select the pool file.
10. Allow Blackboard Ultra to process the file.