Here's a new one on me. It would appear that after using wi-fi, my SD card stops being recognised - I can't think of anything else that I've been doing to cause it. The only way I have been able to get the card to be read by the phone is to switch off, remove the card, put it back in and switch on again. It then works fine - until I use wi-fi again. It's a Lexar 16gb card in a Sensation running ICS - and I have been able to back it up to my PC using the Lexar card reader that came with the SD card (phew!). Anyone know of something I can do?