Team Dashboard v3 - using a "Start date" filter (Team Dashboard sheet) breaks Cumulative Flow chart (More Charts sheet)

[busywait]

Enter, for example, 2015-03-01 as the Start Date on the Team Dashboard sheet.

Look at the Cummulative Flow chart on the More Charts sheet.

Most of the work in progress has disappeared.

I expected to see the correct amount of work in progress over the range shown.