After struggling with the lights a bit, I finally go the lights working continuously:
Previously they would follow their program correctly for anywhere from 30 seconds to several minutes. Inevitably however, the lights would freeze and stop changing. I would then have to power cycle the ray and restart the program.
The answer were a pair of pull-up resistors on the clock and serial lines. These hold each line at +5v or a logic '1' . The devices connected then just have to pull the lines down to 0v to send a signal. The resistor values I had were the recommended values but were actually too high (1oK ohm) for the configuration I was using. Reducing these to 1K ohm did the trick.