I'm guessing you haven't updated firmware lately. [a href=\"index.php?act=findpost&pid=93108\"][{POST_SNAPBACK}][/a]
Quite right, Eric. I generally don't bother with firmware updates unless I've noticed a problem that needs fixing or an additional feature that I want. If it ain't broke, don't fix it. However, you might be right that this problem would not have occurred had I updated the firmware. It's difficult to say because it's happened only twice in the 15,000 or so RAW images I've taken so far with the 5D, and both those occasions were around the same time.
I suspect this problem has something to do with the fact I don't use a mouse with my laptop. I've noticed a few times odd things have happened when moving the cursor around using the touch pad, such as entire folders disappearing because I've accidentally shifted them to a different directory.
However, John's suggestion has worked (thank's John ). Converting the Canon RAW to DNG has fixed the problem. The file is now the correct size, but I'm still curious as to the significance of these 2 little arrows in the lower right corner of the RAW thumbnail which have got there, I'm sure, because of an over sensitive touch pad.
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