DataTables FixedColumns scrollbar not resizing properly

I have a table on which I am using the DataTables FixedColumns plugin. I'd like for the scroll bar to resize to be only underneath the non-fixed columns, as it is in the example page here: https://datatables.net/release-datatables/extras/FixedColumns/index.html

While using the exact same code, I am unable to make this work. Based on some recommendations in the forums, I switched to the nightly builds of DataTables and FixedColumns, but that has not gotten me anywhere.

Illustration of the problem: http://jsfiddle.net/Ue6Gn/1/

Any ideas?