Hi,
Thanks for the post. Basemap layers within ArcGIS for Desktop (ArcView, etc) are not typically supported for packaging or publishing as services because they are designed to behave in a particular manner within ArcMap in order to provide great performance with large background layers.
However, the analyzers (which alert you via the Prepare Window) should pick this up when packaging so this is something we need to take a look at.
Thanks again for the feedback
Cheers
Mike