EDIT: Someone in our tech department upgraded our CUDA drivers to v6. This was incompatible with my system.
I launched AE today, and it gave me this error.
I have rendered a ray-traced comp in the new version, so I know it was working fine initially. I've gone through a couple of power cycles and double-checked the NVIDIA driver to make sure it's the newest available. I don't really care about ray-tracing so much, but I really liked using Fast Draft.