I think somebody was struggling with this inability a while back, but it might have been on another forum to be honest.

Quote from Engadget.com
"We're running the update now and the changelog that shows up on the PS3 has two new features we hadn't heard about: simultaneous audio output across connectors and control of video playback (slow motion, fast forward and rewind) using the right stick."

With great power comes Awesome irresponsibility.