For the last few weeks I've been getting frequent 'not requested' looping (usually about 15 sec) on 2 different computers - one XP, one Win7 - different servers - both Chrome and FF - VLC 2.1.2. I believe it happened also on 2.1.1 as have recently updated and don't know whether the looping pre-dated update.
It can happen on even passive playing of VLC (both own videos and radio streaming) - that is - no multi-tasking going on.