Are there any developers out there that have seen this or know what causes it. More importantly how to get rid of it.
I do recall one time when I had a double uv mapping that was causing havoc, but don't remember how I dealt with it in Blender. I don't know that this is the cause though.
See video.
The mesh disappears at certain angles or distances and the buttons are not hot at certain angles.
P.S. Stuart, if you see this. Notice now only one PDF has the weird cyclic artifact. I don't know why and I also don't think it is consistent that the right PDF doesn't do it.
I did apply you patch the c172p successfully, thanks. Works here as well, not the patch but the concept.
EDIT:
I just watch the video and noticed my mouse was not captured correctly. What i saw when doing this was the mouse was in the correct location over the objects but not active until I changed the angle.