Hello, I had the same problem with all 5 of my players running firmware 2.02.32. So I rolled all boxes back to Firmware 2.01.86 and that solved my problem. So if your box has firmware 2.02.32 then that might be the problem.
To roll back got to http://community.wd.com/t5/WD-TV-Live-Streaming/2-02-32-Firmware-no-longer-allows-content/m-p/781937#M32423
Hope it helps