Playing Simultaneous Output On Ubuntu 9.10

I use Renoise on Ubuntu 9.10 amd64. It usually works fine, with or without Jack. But if I open Renoise when I already have some audio application working (for example, Firefox playing a video on youtube, or an mp3 player, or totem) it doesn’t work because it says the audio device is occupied by another application.

If I first open Renoise and then try to play an mp3, it doesn’t work either. It’s not just that it doesn’t play the audio. It doesn’t move. I mean, the position bar doesn’t advance.

I read in the Linux faq to use Alsa, but I’m not sure how to do that. So I looked at the PulseAudio preferences and there’s an option to enable simultaneous output. This didn’t solve anything at all, but there’s a difference. If I open Renoise and then try to play an mp3 I can’t hear the audio, but the bar does advance this time.

Any idea? Is there anybody that can actually use Renoise and other audio application?