Okay, this is weird. I put the SAME bulb back in that I took out, and now it works. Weird! I took the bulb out to test it and left it out for a day (took it out over lunch time at work). Today when I reassembled to await arrival of my new/used dome light assembly, it started working again.
Now if I can just talk the seller into sending back my Paypal payment. D'oh!