Help with using idle trigger in Win Task Scheduler

OK I know i've bombarded the forums lately with a couple threads all somewhat related.

Point of this thread -- how to correctly set the idle trigger in windows task scheduler.

There is a MSFT article Task Idle Conditions (Windows) which tries to explain it, but I can't figure it out.

I still don't understand what the "Wait for idle for" means. Also, the article says Windows checks the system every 15 minutes, so does that mean any time less than 15 minutes would not work?

Has anyone successfully used the 'idle' as a trigger? I want to run a program (namely shutdown.exe /l) when computer is idle for 17 minutes. I want to pop up a message at 15 minutes saying it'll log you out in 2 minutes. So I want to set two tasks, both on idle triggers, two minutes apart.

I tried two ways of the trigger --
1) When computer is idle, and set conditions of idle
2) At log on, and then set conditions of idle

I've waited and waited to see if it would work and it does NOT! Any and all help appreciated.

Did you ever get an Ideltime trigger to work in Windows 7 task scheduler? If so, please do tell me how!

Resurrecting this thread as I can't find a definitive answer anywhere and I would really like one.

I found this -

New Task on Vista and Later

Which includes the only explanation of "Wait for idle for" i've found that makes any sense at all. Even then it's really more to do with poor language of the prior "Start the task only if the computer is idle for" option.

No I haven't been able to get it to work. I got what I wanted (log out @ 15 minutes idle) using a program / screen saver called screen saver operations.