I found my own answer--and decided to post it in case it helps someone else.
I went under "Applications" in my setup menu, found the WWF, and cleared both the cache and data. After it reloaded, everything was back.
I think the genesis of this problem is playing on the go with an unreliable 3G connection--and getting only partial data before connection is dropped. Perhaps this corrupts the local (on the phone) data file.
Hope this answer may help someone else.