Multi-row Push/Pull layouts

When using the Push/Pull options to rearange the columns of a section, you get strange results if the widths add up to more than the number of columns, so that the the last one is shown wrapped to a second row of regions.

An example:
Side Bar 1: Push 0, Width 3, Pull 9
Content: Push 3, Width 9, Pull 0
Side Bar 2: Push 0, Width 3, Pull 0

which shows as

Side Bar 1 Content
Side Bar 2

in the actual page display the Side Bar 2 data is displayed overplayed on the last 3 columns of the Content region.