So hello,
I have this problem with mine Sandisk micro memory card. The problem is that it won’t work when I put that card in to my Sansa Clip+ player (When I plug-in my card the player just don’t respond) or Sandisk adapter (my computer don’t read the card), but the card works when I put it in my mobile phone. Also I have an old micro sd 128mb card from my mobile phone and this card works perfectly in my Sansa player and Sandisk adapter. Maybe anyone could help me, I would appresiate it.