The Tips in detail

 "Video Post: Glow - visible through transparent objects?"

VP Glow is only visible through raytraced objects. So if you'd want to have a VP Glow behind a screen (for example) you'll have to use a raytraced material for the screen itself in order to make the VP Glow visible through the screen.

The plugin X-Ray is told to make VP-Glows visible through objects.