Qml TaskbarButton from QtWinExtras 1.0 crashes app on Windows 7 with Basic theme

import QtWinExtras 1.0
 
ApplicationWindow \{
   //---------------------------------------------------------------------------
  // Windows taskbar progress
  //---------------------------------------------------------------------------
  TaskbarButton \{
    progress.visible: true
    progress.minimum: 0
    progress.maximum: 100
    progress.value: 75
  }  
}