[William Sommerwerck]

eMedia was kind enough to send the current version of "Piano for Dummies" at
no charge (once I surrendered the version I already owned). This fixed the
problems. The program can now play the keyboard.

The keyboard can also be set to play through the computer, but there's a
noticeable delay (which you're warned about). The MIDI interface must present
an incredible amount of overhead.

Am I unreasonable in saying that MIDI doesn't always work the way you think it
"ought" to? This is an issue that most documentation (on any subject)
generally fails to address.

Again, thanks to those who responded to my initial request for help.