Hi,
Please note that if you trying to migrate from QC 10.00 server to ALM 11.52 you will not be able to do the import and export function this because the functionality will only work when you have the same verison of the QC/ALM.
In this case the best prodedure that could be taken is the restore option.
For more information please refere to: http://support.openview.hp.com/selfsolve/document/KM00474177
Note: If you need furder support please open your question in the following forum link:
Regards,
Kael