After more research I found bug #533135 "System fails to boot with plymouth installed (nouveau driver with >1 display)" which seems to more accurately fit the symptoms I'm experiencing.
-- NV18 GPU lockup with Nouveau https://bugs.launchpad.net/bugs/537741 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
