I can confirm Peters suspicions that there are no functional changes between R101 and R102 with regards to video rendering.
We have no plans to make that available from the CMS - it is a configuration time client side option (the device needs to enumerate its available storage methods)
Due to changes in the way SD cards work in Android, we needed to rewrite how these were parsed and shown in the options page - neither would have been checked as a result of this, however the existing setting would have been honoured until you selected a new one.
If the video fails to play with an error from the underlying media player, it will always log the message - unless it has had a "what=something other that 100" - in that case the file gets blacklisted and will be shown in the blacklist on the status screen.
Edit: as a matter of interest,
what=100 means that the MediaServer on the android device died and was not able to continue (or start perhaps) rendering the video. The correct thing to do in this case is move on and try again (which is why no blacklist in this case).