Thanks so much for your help! The camera was set up for DHCP; setting a static IP address got it back online.
FOR THE NEXT GUY WITH THIS PROBLEM:
The process of setting up a static IP address isn't very straight forward. I tried to do it using the advanced settings link from mydlink, but lost contact with the camera. It wasn't coming back up on mydlink after the change. I had to hook the camera up directly to the router via an Ethernet cable and run the setup wizard to get it reconfigured. I learned the hard way that you need to set it up first as wired, let it connect to mydlink, then go back in with the setup wizard and configure the wireless connection. (This is critical on the initial setup, so that mydlink can upgrade the firmware.)
My router is an older Linksys WRT54GS2. It's configured for WEP security. For some reason, when I went back in to setup wireless, it didn't show my network on the list of available networks. I had to manually enter the network name, select WEP security, etc., to get it configured.
I got the static IP parameters in part from copying what my desktop shows via the command line ipconfig command. The DNS addresses are those used by my router and are Google's DNS servers. My router's DHCP address range starts at 192.168.1.100, so I just picked something below that and hoped that it wasn't already in use. (I don't know how to get a list of IP address that are in use on my LAN; maybe someone knows?)
Here's my camera's IP configuration, etc.:
Basic information
Camera Name DCS-932LB
Time & Date
26 Feb 2017 9:19:55 P.M.
Firmware Version 2.14.04 (2016-09-09)
Hardware Version B
Agent Version 2.1.0-b41
MAC Address XX XX XX XX XX XX
IP Address 192.168.1.81
Subnet Mask 255.255.255.0
Default Gateway 192.168.1.1
Primary DNS 8.8.8.8
Secondary DNS 8.8.4.4
DDNS Disable
UPnP Port Forwarding Disable