Update #2: Ok, I figured out the issue. Apparently the internet interfaces are not being brought up on the WD TV until after the ddclient load script runs. I would have thought that it would simply catch it on the next run, but apparently ddclient fails on subsequent runs if it can't find the ip address provider on the first run.
I have made some modifications to do exactly what you suggested, i.e. delay the start of ddclient for about three minutes to make sure that the internet interface is brought up before ddclient starts running. I tested this on my box, and now the ddclient.cache file (i.e. the one that contains the info about your current ip address) is being correctly created and populated.
I have also changed the provider of the ip address, since as mentioned in my last message the checkip.dyndns.org is really flaky (specifically, there are really three servers around the world that answer to that dns entry, depending on where you are located - one of them works great, the others fail frequently).
I'll try to upload a new app.bin with the changes tonight - when I do, please try it out and let me know if it works for you.