G'day folks, sorry the image stacking guide hasn't been available for a while. I shut down ASIGN Observatory a while ago and have been busy with the new ASIGN Observatory II upgrade.
Today I am stuck at home with the flu and lots of time, so I transferred the page onto the new site.
http://asignobservatoryii.webs.com/tutorials.htm
If you're new to all of this, I hope I can help you get started!