I recently exported an existing universe into a new repository. When I import back into BusinessObjects all of the relationships and joins seem to disappear.
I also have exported a different universe into the same repository, and when I import back into BusinessObjects it appears to be fine.
It sounds like there may be a spacing issue on the Universe Domain. The joins are one of the last things to export. If they do not successfully export (they SQL will NOT be kicked back if the extents aren’t large enough to contain the data) they will not be there on the import.
Try increasing the size of the tablespace. Also try running a: Scan/Repair and Compact on the Security Domain and try again. This will free up space by deleting all of the references that were just marked for deletion.
You can also try deleting the original and running the Scan/Repair and Compact before reexporting it. See if that makes a difference. Also check to see if your system is the only one with the issue (it could be local).