Same problem here. I also experience random lock-ups (approx. twice a week) on both my WD TV Live boxes when watching Netflix. Only solution seem to be to unplug/plug power cord. I am currently on firmware 1.16. My experience is that before the lock-ups happen, the responsiveness declines gradually.
Firmware 1.15 was much worse, though. Lock-ups happened at least once every evening.
Firmware 1.13, on the other hand, was much more stable…
Another issue that I have with both my WD TV Live boxes is that the HDMI signal is not always picked up by my TVs (Philips TV and Sony TV). I often need to toggle the power on my WD TV boxes to get a proper signal on my TVs. Apparently the WD TV boxes have a general HDMI issue.
I’m quite dissapointed by the quality of the WD TV firmwares and HDMI output.