I had a couple of instances where *something* happened when I took the SD card of my old K100D and plugged the card into a third party reader. The images were fine in the camera, and then the reader gave me file errors, eventually leading to rescue software and other tears. I've had similar instances when an SDHC card was mistakenly placed in a standard SD reader device....errors and data loss.
Yeah, slower and not very hip, but I KNOW I can get the images off the camera with the USB cable ... I can spare a couple of minutes.
Good question!
germar