I was very disappointed with my new Centro. It does not accept 4GB card! I went to the store twice to have the 4GB replaced, still no luck. So I settled for a 2GB. With the 4GB, the Centro displays "No card is inserted" or something. I even called Sprint Tech support to verify that the Centro indeed is compatible with 4GB micro SD-HC. Tech support said that it does and it is on the specs. Anyone here using a 4GB micro SD? What brand? I bought/returned a Kingston brand 4GB card.