I've upgraded from the Canon 50D to the Canon 7D as my secondary body for weddings. It hasn't been put to the test yet until this past weekend.
After shooting a little over 500 photos with it, I had about 3 photos that came out like the one attached in the photo.
This was shot with the Canon 7D w/ 580EX II Flash Mounted, Canon EF 70-200 f/2.8L IS USM, and the original OEM battery. The memory card is a Kingston Elite Pro 32 GB.
Anyone else experiencing this issue?