Incorrect Calculations for Required Daily Burnup Rate

The Burnup Chart miscalculates the required daily burnup rate and doesn't match rate from required daily burdown rate (from burndown chart). Something is broken in the way the burnup chart calculates the required daily burnup. See the attached file for an example chart that miscalculates the wrong burnup rate - Starts at 2, drops to 0!, slowly increases, but math doesn't work - 13 points and 6 days remaining in sprint, but calculation says daily burnup rate of 4 points required! Also, "ongoing" story point dotted line shows we're closing 2 points soon, but that makes "ongoing" burnup rate jump to 5 points required! Something's very wrong with this calculation.