Weird. Maybe try a different USB cable? Or test with another computer?
Switched USB cables. No dice.
Then tried connecting to my wife's Windows machine (for which I have now installed Arduino software). When I got to Step 3 of the Getting Started w/ Arduino on Windows page (http://arduino.cc/en/Guide/Windows
), plugging in the board causes the green power to light up (and the Blink program to start, just as it does when I plug into my Mac), but Windows doesn't
begin its driver installation process as Step 4 suggests.
So this suggests to me that either the board or the AVR has a problem. Any suggestions? I do
have an STK-500 at my disposal if someone can suggest steps to take on the ATmega328.