I bought this TV earlier this week.  It has firmware PKG2.263EUA installed.

When I play SD (typically 1,000 Kbps) quality MKV from USB, I may notice frame skipping infrequently. There is no interuption to the audio.  It occurs randomly, perhaps may be once or twice in a minute at worst and only lasts only a split second in duration.  If I rewind the video a few seconds and play it again, there is no frame dropping at the same time index.  It seems to be worse with MKVs than MP4 files.

I've tried both USB sockets and using different pen drives.

The issue also appears over DLNA (no transcoding) too.

My EX723 doesn't exhibit this issue when playing the same MP4 files via USB.  It can't play MKV files.

The MKV files play back perfectly smoothly using WD TV Live Media Player (24p mode) connected to the EX723 and W705 TVs (which reports 1080/24p when I press the 'i' button)

However, it does remind me of similar random dropped frame issue I witnessed when I incorrectly set the WD TV Live Media Player to 'Auto' instead of '24p' output mode when viewing on my old EX723 TV.

A search in this forum revealed this similar case but it is for W905.

http://community.sony.co.uk/t5/televisions/kdl-55w905a-stuttering-random-frame-drop-s/m-p/1488492/hi...

I've tried different scene modes, Auto (24P), General and Cinema.