Symptoms
When paging is enabled for the view, the sort order is ignored using a custom broker.
Diagnoses
This is a issue in the smartobject core and all out of the box and custom service brokers.
Resolution
LABS built a fix for the custom broker and it has been sent to the client. An item has been logged in TFS to implement this across all smartobjects. This is a big architectural change and will take time. But, this should be implemented in a future release.