Maybe totaly unconnected but I had this very problem a while back...it was my ISP capping services secretively.
I am in the UK and was with Sky connect....moved back to BT and the problem along with many others I had in SL vanished (no music/groups/Death by TP/& more) . the same happened to me...TP into a live music event starkers to everyone else when on my screen I was clothed
Just a thought and hope it helps someone if not yourself.
R