You may need a graphics adapter update
•What is your exact brand/model graphics adapter (ATI or nVidia or ???)
•What is your exact graphics adapter driver version?
•Have you gone to the vendor web site to check for a newer driver?
•For Windows, do NOT rely on Windows Update to have current driver information
•-you need to go direct to the vendor web site and check updates for yourself
•ATI Driver Autodetect http://support.amd.com/en-us/download/auto-detect-tool
Please double-check that the same sequence that's open in the current Timeline is also loaded in Program Monitor. We recently discovered a bug that resulted in the Program Monitor having a different sequence loaded than the active Timeline. The scenario in which this occurs is as follows:
- Open two sequences (or more) in the same panel, say Seq_A and Seq_B.
- Set focus on Seq_B.
- Maximize the Project Panel.
- Double-click Seq_A in the Project Panel.
At this point, the Project Panel reverts to its normal size and the Program Monitor loads Seq_A, but Seq_B remains in front of Seq_A. This disconnect persists if you set focus on the Seq_B Timeline; when Seq_B is played with things in this state, you will hear that sequence's audio, but the Program Monitor will remain static.
This is not likely to explain your situation, but it's worth ruling out before pursuing further troubleshooting.