I had been trying to get the IdeaCentre Q700 to play DVDs. They would play properly up until the actual movie started to play.
Then, the screen would freeze. This occurred regardless whether I was using Windows Media Player or VLC or even WinDVD.
The fix was in BIOS. There is a setting for protected video path which enables HDCP over HDMI connections. This keeps Hollywood happy.
As Lenovo ships the system, the PVP is in the off setting. If you set it to the middle setting, reboot, and video playback will work just fine.