I recently authored a DVD. Is there a way to make it into a Blu Ray using the same project settings?

All my titles, menus, etc are in 720x480.  I'm not sure how to upscale it. 

I tried just exporting as a Blu Ray, and the quality is terrible, the video menus are all screwy.  Also, I am getting Media Offline messages on footage that works perfectly fine on DVD. I tried burning straight to disc and also to an ISO.

Thanks.