not sure how common this one is but i just bought a 512 meg SD card..
bunged it in my camera took about 300 megs of pics...
put it in my less than a year old card reader and did as i norrmally do and drag and drop wise moved the pic folder from my card to my hard drive.. all seemed well all the pics showed up.
when i got to viewing the last 30 or so pics i got "cant read file header" error messages. hmmm
duff card duff camera or just a fluke.. in the end it turned out to be a card reader problem basically my card reader dosnt have any idea what a 512 card is.. it only reads/stores properly up 256 meg any thing over isnt readable.. i had to bang off 500 megs or so of pics in the camera and use the camera to transfer the pics to find this out for sure.. but its definitely the card reader..
the bad thing is the card reader appears to read and copy/move the pics.. files names show up and everything appears to work okay.. but after move/copying they are just unreadable over 256 meg..
something worth noting i recon it could have lost me a lot of pictures.. like 256 megs worth.. he he
its safer to copy as apposed to move.. this is what killed mine.. copying would have at least left the pics on the card.. at least make sure that the pics are on the hard drive before deleting em off the card..
trog100