I've just upgraded my 15.04 machine to kernel 3.19.0-32, and I continue to experience this bug, as I did with -30 and -31. The suggestion in comment #32 above (https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/1386005/comments/32), which is to set GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" in /etc/default/grub, does not change things for me.
I've just upgraded my 15.04 machine to kernel 3.19.0-32, and I continue to experience this bug, as I did with -30 and -31. The suggestion in comment #32 above (https:/ /bugs.launchpad .net/ubuntu/ +source/ plymouth/ +bug/1386005/ comments/ 32), which is to set GRUB_CMDLINE_ LINUX_DEFAULT= "quiet splash" in /etc/default/grub, does not change things for me.