jQuery UI sortable table width problem

The jQuery UI sortable allows different rows in a table to be rearranged by dragging a row to a different position. They recommend using a UL with LI elements which you drag around, but table rows inside a TBODY work too.
Drag a row up or down to test.
Name Age Gender Favourite ice cream Favourite sport
Joe Bloggs 25 Male Chocolate Soccer
Jane Doe 44 Female Mint Dressage
Matt Headon 34 Male Strawberry Baseball