Changing the IP of the router was the very first changed after removing it from the box.  No other settings had changed.  I changed the IP back and started using it.  Since that time, I have changed several other settings.  (I didn't keep track of which changes I made.  An example is: I configured the ntp server.)  I was going to add dhcp assigned addresses, so it seemed like a good time to test the problem again.  From my laptop (a different computer from before) I switched back to 192.168.73.1 and to my surprise the site worked.  All the labels were present.
I moved to my desktop and found that the labels still were absent.  "hm." I thought. "Maybe there's something to this browser business."  I installed a USER_AGENT switcher in chrome and tried reloading the page with a different user_agent value.  After several tries with different user_agent values, tried it with Firefox 6 (I think) it started working.  But, it didn't stop working when I switched back to the default USER_AGENT value.  So...  what's up?
I suspect that what "fixed" it on my desktop computer was the continual reloading of the page; not changing the user_agent value.  I haven't done any other tests.  (As I said before, I'm not really very interested in finding bugs.  I just want it to work.)  But, if I come across this problem again, I will attempt repeated reloads of the page (it took less than 10, I think).  I will post here again if/when I have more information.
- anaj