Posted this a month or so ago but have new info and samples that may(?)
help diagnose problem.

Went to Africa for 3 weeks last Sept. with a new Panasonic Lumix FZ-10
and 2 Panasonic SD cards - a 256MB and a 512MB - that I  filled w/
1600x1200 pix.  Came home and imported the jpg files to my iMac G5 and
burned backup DVDs. The Lumix can be hooked up to a TV so we ran slide
shows for friends and family of all the pix from the 2 cards.  Images
were great on our big Sony - crisp, great color, and I could pause an
image and use the camera's playback zoom to enlarge an image.  And the
focus held nicely as I zoomed.

For Christmas, my brother gave me a Lexar 1 GB card and I decided to
consolidate the images from the 2 cards onto the one for convenience
sake. (Still haven't edited and after I do, will make a shorter show
and burn to DVD.  But, for the time being, still fun to show on big
Sony TV and zoom in on areas.)  Using USB, used a Memorex multimedia
card reader to copy all the jpg's from the iMac to the 1 GB card.

After confirming that they were all there, I connected the camera to
the TV and discovered many pictures were now out of focus.  Reconnected
the card to the iMac and, when I tried to use Preview to view, was told
the out of focus files were corrupt.  Tried to open some with Photoshop
on a PC at work and was told "The document may be damaged (the file may
be truncated or incomplete). Continue?"  When I continued, I saw a band
at the bottom that looks for all the world like a copy of a band from
the middle of the image.

When I can open damaged files with some programs (e.g.,. Microsoft
Photo Editor), they don't appear out of focus.  Nor does the sample
I've put on Flickr -- see below.  But they are out of focus on the
camera's LCD and on the Sony.

As I said, I can/will make a slide show from the files on the iMac
which appear to be just fine.  But I'm trying to figure out what might
have happened.

Problems with the Lexar card?
Problems with the card reader?
Problems transferring a ton of images?
Why just some images and why only out of focus on the camera and TV?

Note: there's an "All Sizes" button above the images below that will
allow you to view in a variety of sizes including the original
1600x1200 FWIW.

Good original:
<http://www.flickr.com/photos/jrosinia/1264452/in/set-28924/>

Damaged/corrupt:
<http://www.flickr.com/photos/jrosinia/8009852/>

Sorry to go on and on but I've been wracking my brain about what might
have happened and wanted to give you as much data as might be
necessary.  Any thoughts would be most appreciated.

J