Here's my report.
I tried and tried, but cannot program the Icon modules with the PalmPad.
They programmed fine with the CM15A, though. After putting the Icon in program mode, I'd click with the mouse to turn A1 on, then off, then back on. After the third one, the Icon light would stop blinking, burn steadily, and the module now works fine to turn the display cases on and off when A1 signals are sent from the motion detectors.
The Icon modules are indeed almost completely silent. Just perfect for our needs.
I did a little looking around the net and ran across one post on the Smarthome site that said the PalmPad will not program the Icons because it sends both House Code and Unit Code at the same time, and the Smarthome stuff can't handle that. On the other hand, controllers like CM15A and PHC02 Maxi Controller send House Code first, then Unit Code, and that's what Smarthome modules expect.
So anyway, I'm in business now and things are going great. Thanks!