I have worked in professional video for years and have seen similar problems on other equipment.

If all, or almost all, your DVD titles exhibit this problem, it is likely an equipment problem. If it is only one or two particular disks, then it is likely a probem with those disks. This is the first "test."

In all likelyhood, it is not the 950, unless other video and audio sources connected to the exact same set of inputs also display the exact same problem. When you test another video/audio source, don't use the same cables as with your DVD player, in case the problem is in the cables.

If other video/audio sources remain stable using the same inputs with different cables, it is either the set of cables you started with, the player itself, or that particular DVD disk. The fact that there are problems with video and audio simultaneously would seem to indicate the player or the disk. If other disks play without problem, I would say it is that particular disk on your particular player.

The fact the the 950 on-screen menu jumbles when the video source jumbles is not surprising. The 950 is likely working with the timing of the incoming video sync signals of the source. If the source sync has problems, the menu display will follow.

Television monitors, by design, can operate with widely varying sync levels. Video processing equipment has more restrictive limits. This is partly how DVD copy protection works. If you try to run the DVD video of a copy protected disk through a VCR, the image will periodically lighten and darken because of variations in sync levels that the VCR uses for reference. The monitor itself does not rely on sync levels in the same way a VCR does, so if you what the DVD directly to a monitor, you don't see the darkening.

This type of copy protection passes through my 950 to my monitor without any problem.

Your sync problems sounds like an sync interruption or sync timing issue, not a sync level issue. Since audio is interrupted at the same time, I would suspect the source player or disk, not the video or audio path.