JB's 3D concert movie director walks out

Uh-oh, Justin Bieber fans. The teen heartthrob's 3-D concert-movie extravaganza has hit a roadblock: Oscar-winning filmmaker Davis Guggenheim has reportedly dropped out.

According to Deadline.com, the "Inconvenient Truth" director withdrew from the Paramount Pictures project Tuesday night to concentrate on promoting Sundance darling "Waiting for Superman." Paramount is said to already be