How do I get a Task Scheduler startup trigger to delay

Question

System is Windows 2008 R2

I have a task scheduler task with a trigger to run at system startup, and have set the Delay to 20 minutes, however the task runs immediatley on system startup and ignores the 20 minute delay. There are other triggers, but it is the boot trigger which is at fault by ignoring the delay.

Triggers section of the exported task follows.

  <Triggers>
<CalendarTrigger>
  <StartBoundary>2009-12-29T08:35:00</StartBoundary>
  <Enabled>false</Enabled>
  <ScheduleByWeek>
    <DaysOfWeek>
      <Monday />
      <Tuesday />
      <Wednesday />
      <Thursday />
      <Friday />
    </DaysOfWeek>
    <WeeksInterval>1</WeeksInterval>
  </ScheduleByWeek>
</CalendarTrigger>
<BootTrigger>
  <Enabled>true</Enabled>
  <Delay>PT20M</Delay>
</BootTrigger>
<CalendarTrigger>
  <StartBoundary>2012-07-29T18:07:16</StartBoundary>
  <Enabled>true</Enabled>
  <ScheduleByWeek>
    <DaysOfWeek>
      <Monday />
      <Tuesday />
      <Wednesday />
      <Thursday />
      <Friday />
    </DaysOfWeek>
    <WeeksInterval>1</WeeksInterval>
  </ScheduleByWeek>
</CalendarTrigger>

Solution

I added a new task with only one trigger - the BootTrigger with delay. This time the delay did work. So there must be some bug where a boot trigger delay does not work if multiple triggers are present.