My WDTV Live is attached via HDMI to a Sony KDL-46W5100 TV. I recently upgraded my WDTV Live from firmware version 1.02.21 to 1.04.10_V. During movie playback on 1.04.10_V, I was getting flickering where the screen would go black for a split second. After searching this forum, I tried the usual things such as power cycling the WDTV Live. Nothing worked. Alas, I decided to rollback the firmware to 1.02.21. That fixed it.
I have two words for the Western Digital developers: regression testing.