So my phone regularly corrupts anything added to the SD card, even with various brand cards; all larger than the stock 2GB. I’d bought a 32GB one and though maybe it couldn’t handle that size (apparently it can) so went down to 16GB; still photos are corrupting as are podcast downloads, dammit!
Some people said it is linked to the phone not supporting certain class SD cards, some say certain brand, some certain size.
Bizarre fix that worked for me? Connect and mount your phone to your PC or use an IO File Manager app on the phone itself; open the two configuration xml files in the root.
Are they corrupted? Delete them and reboot – new ones are created and the phone works again.
Doubt this is in any way a long term solution, but it stops me throwing it out the window.
No warranties, it works for me, YMMV, etc.