So I bought a Crucial M4 256 GB drive almost exactly a year ago. (Two weeks left.) The problem is, the amount of space used and free is highly variable, with no interaction from me. I'm not talking a gig here or there. I keep my drive relatively empty, typically with 100 gigs or so free. But just yesterday, it plumpeted down to 50~ gigs free and currently, I have 168 gigs free. Is this a sign of how SSDs fail? And if so, how should I go about resolving this? Contact Amazon or Crucial and ask for a replacement?