Here's a question: I took pictures of sunrise in the SF Bay Area and I noticed that there was a 10 minute gap in my pictures that shouldn't have been there (I didn't stop shooting...) and I checked my card. Now there are a series of about 40 shots that are all .NEFs but they cannot be opened by photoshop, nor my D90 when I put the card back into the camera.
Anyone have this happen to them before? Potential causes? This is with a SanDisk 8GB Ultra II