I have updated my 12.04 HTPC to 14.04 (new install; same hardware), and have started getting awful screen tearing where I had none before.
AMD A4-3300 APU with Radeon(tm) HD Graphics
01:00.0 VGA compatible controller: NVIDIA Corporation GT218 [GeForce 210] (rev a2)
nvidia 10675249 71
drm 302631 2 nvidia
Everything is from the official repos.