Hi I have the same problem with my two WDTV Live Streaming devices. My wife was using one of them primarily for viewing videos on YouTube. It would be disappointing if there would not firmware upgrade to resolve the issue.
I just received an email from WD support about my inquiry into Youtube. From this statement from [Deleted]:
_ We are currently looking into the inconvenience discussed regarding the YouTube Leanback App. As soon as a fix is obtained, we will be releasing it in a future Firmware update. Unfortunately, we would not be able to provide you with a time frame in which this Firmware will be released. _
It does seem that there is some activity with respect to a firmware update. Unfortunately, there is no timeframe commitment. In spite of the fact that I am not happy with how WD has performed with respect to firmware maintenance on the SMP, they have been nothing but courteous and professional in their dealing with me via email.
It sounds like u have memory leakage slowing/breaking Leanback. Do a hard reboot (5s long press of power off button) to do a total restart of system. Other apps also leak, including a system Library compilation (if u have Media Library on).
As for a fix, join the queue! We all want one but WD seem to have done a last release and abandoned us with a very damaged last firmware.