Hi Ace,
Did you try to open this example directly from the zipped folder? You'll receive an error if you try to open it without unzipping it. Also, the instructions on the front panel of the "bring forward" VI mention that you need to have the subVI open for the example to work.
I'm not sure why you would see a lag, unless it is related to the error. When I select "case 2" the subVI stops without any noticeable lag.
If you are still getting an error, you may want to tell us what the error says.
Luke
Applications Engineer
National Instruments