Figured I would chime in.
Had the touch since it came out. One day my files were jibberish on the 512 card. Camera also had "lines" in it so I took it back. Got a new touch. Had it happen again. Got a 4 gig transend card, happened again. Returned card and got another 4 gig. Did it again with a twist.
I was at supercross taking pics and I couldnt view them. I looked in the folder and there was nothing in the DCIM folder. I could not erase the folder or anything. I would take a pic and it would not store in the card. Then I renamed the folder DCIM (all it would let me do) and then it worked again but my previous 15 pics were gone.
Now the other day I could click on the mail messenging or text messenging buttons and they highlight but wont open. Also I cant recieve texts. Pop out the card and then it works.
Put my 512 back in for now since I missed a lot of texts.