Alex, thanks for the reply. Littlebits support has already contacted me and is sending a replacement.
The speaker is set to ALL, not ONCE. It has always been a bit flaky anyway. Although he can get everything to work, every time the unit is powered on he has to jiggle, wiggle, disassemble, and reassemble to get everything working and sound to come out. Once he does that, everything will usually work until the unit is powered off.
I don't have the oscillator yet. My sister gave him a $100 Littlebits gift card so we are debating what to get next. So far he's got the Arduino Kit and then a random assortment of bits that he needed for his science project - mp3 player, synth speaker, motion sensor, time out, etc.