Problem solved! When the main window opens, the Control
section is not visible. That section contains the Start
button. You have to pull the bottom border of the window
down to see it. This is true on Linux and Windows 7.
The window could be smaller - it's the full height of the
screen on a netbook. At least there should be a scroll bar
whenever the entire dialog contents don't fit into the
window. Am I the first to notice this? I'll bet that the
developer always runs the app full-screen.
Now I just have to lurk on the ham bands for some suitable
traffic.