iDemo doesn't show up in a screen capture on XP

You might find that doing screencast of iDemo on XP doesn't capture the iDemo window.
This is because the whole WPF framework uses accelerated drawing routines. On Vista or Seven, the desktop UI is accelerated by default, so capture programs don't have any issues there. On XP, which is an older operating system, the desktop isn't accelerated, and therefore most capture applications won't capture accelerated drawing.

There's a workaround though.
If you're using Camtasia, in Camtasia recorder go in Tools / Options, and in the General Tab, Capture section, check the "Disable display acceleration during capture" checkbox.

For other programs, you have the option to disable the display acceleration globally, by bringing up the Display properties, then clicking the Advanced button, and selecting the troubleshoot tab.
Set the hardware acceleration slider to none, and iDemo will show up in capture programs.