I just had this very same thing happen to me. I'm not sure if you're having the same issue or not, but here's what happened in my case:
Earlier, I had ejected a CD via the eject button, not through the UI. The CD remained mounted, and still showed up in the Nautilus sidebar. I tried to burn an Ubuntu disc and got exactly the result you're describing here. As soon as I unmounted the phantom CD, I was able to burn again. Check and see if you still have a CD filesystem mounted, it'll show in the nautilus sidebar. If not, then you're having a different issue and we'll go from there. ** Changed in: brasero (Ubuntu) Status: New => Incomplete -- Brasero disk burner won't get past "Preparing to write." https://bugs.launchpad.net/bugs/486960 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs