Can I ask how you were able to get Ubuntu installed in the first place with the Radeon HD 7340? I have a Toshiba Satellite C855D-S5320 which has the Radeon HD 7340. When I try to install or even live boot Ubuntu Desktop (64bit AMD), I only end up with a black screen. I'm not asking you to write me a tutorial but just some helpful pointers would be great. I'm specifically wondering if there's a way for me to create a custom install DVD that will include the beta drivers you speak of so that I may get the install off the ground.
P.S., This is my first post here. I'm a Linux newbie.