After installing from CD, I rebooted.  During firstboot's NTP configuration I
entered an IP address.  After waiting on it to do something for over a minute, I
realized that the ethernet cable was unplugged.  I plugged it in, and waited a
bit longer.  During this time I had switched to a different virtual console, and
upon returning to VC7, firstboot did not repaint the screen.... ever.

Upon going to another computer, I got in via ssh.  I found that the cause of the
hang was ping -c 2 <ipaddress> had been running for quite some time.  Upon using
kill to get rid of the ping, firstboot repainted the screen and popped up an
error dialog.  A retry made everything go OK.

There are a couple problems here... 

1) If you are trying to see if a machine is a suitable NTP server, use an NTP
command rather than ping to see if it is alive.  Ping tests ICMP ECHO REQUEST
and ECHO REPLY packets.  A different command such as ntpdate will test NTP
packets.  Since ICMP ECHO REQUEST or ECHO REPLY packets may be firewalled, this
is a bad test to do.

2) If you really insist on using ping, consider the -w option.  I have not
tested to see if it would help in this situation or not, but the info in the man
page suggests that it should.