In my PPA you'll find a new dmsetup package, could you try it out and see whether it makes things better or worse?
sudo add-apt-repository ppa:scott/ppa sudo apt-get update sudo apt-get upgrade
Check you have dmsetup 2.02.54-1ubuntu4~ppa1
dpkg-query -W dmsetup
Then reboot.
In my PPA you'll find a new dmsetup package, could you try it out and see whether it makes things better or worse?
sudo add-apt-repository ppa:scott/ppa
sudo apt-get update
sudo apt-get upgrade
Check you have dmsetup 2.02.54- 1ubuntu4~ ppa1
dpkg-query -W dmsetup
Then reboot.