The card's pinholes where a CF card reader's pins go in are damaged. Didn't notice it until I took it out of my DSLR the first time. The pins in my camera's slot are in normal working order. The card worked for a while.
The reason I gave this two stars is because it worked for a few days and crapped out in the middle of a photo shoot on Saturday. Couldn't access the photos and video through the camera until I connected it to my computer.