Your hubs read duplicate because HubPages has a crawler that surfs the net to find web pages that are similar to your hubs. Even if its your own content, they still will read duplicate.
While this is not against HubPages policy, it will reduce the overall score of the duplicate hub.
One way to fix this is to write unique content for a hub that cannot be found on another site you publish to.
You can still publish your works elsewhere, but it will continue to reduce your overall score.
I hope this helps!