Log Browser will not chart "Power Issues"

Using MP 1.3.52.
When I try to use the drop down choice “Power Issues”, the chart is not created even after several minutes. If I manually select the POWR:Vcc from the tree, then it draws correctly.

In the status tab of MP, Vcc is not listed as a value to display. However, there is “voltageflag”, “boardvoltage”, “hwvoltage” and “servovoltage”. What are these actually showing?