I posted about this a few days ago; guess you didn't scroll down the forums far enough to see it. (
https://www.pentaxforums.com/forums/photo-tips-technique/5172-opening-bad-cor...raw-files.html)
Originally posted by davemdsn It is also possible there is a different problem entirely. I can see a thumbnail for the file in Adobe Bridge, but when I try to open it nothing happens. Lightroom tells me that the file is either corrupt or incompatible.
I worked with Randy for a bit trying to get the image open to no avail. Maybe one of the things he suggests will work for you.
I was finally able to view the embedded jpg thumbnail with Pentax Photo Lab, and Irfan View (on recommendation by jfdavis), but just the thumbnail. The file shows up as a broken image with the Elements 5 Organizer, and all RAW converters I've tried spit the file right back. I used the in-camera conversion to develop the PEF to jpg.
I really honestly think it's just a hiccup (and I'd really rather not see this issue blown into recent VPN-sized mega-issue proportions). If you'd like to point a finger, it might be the camera, because I use exclusively Sandisk Ultra II 2GB cards, bought from high quality vendors (2 from Best Buy, 3 from Sandisk directly, and 2 from Costco). My card usage might as well be kosher, as well.