I hesitated to post this "bug" because it is very complicated to describe and may certainly be unique to resource limitations of my WinXP 32bit system, but one aspect convinced me to proceed.
It involves tree rendering, specifically the palms of SFMA. My system is E8400 @ 3GHz, HD7870 2GB, WinXP 32bit, 8GB RAM (of which XP only sees <4GB), 2048 or 4096 textures make no difference. CM view at <1K alt. Tree Detail set to 18%. As I increase Detail Range from 0.5 mi to 1.5 mi everything behaves normally, i.e. more and more trees fade into view at an increasing radius from my location. However, from 1.5 mi to 3 mi something weird happens: more trees fade into view properly at further radii, but many of the close in trees suddenly disappear. This only happens to the palm trees in the group of eight. It does not happen to non-palm trees or the group of three palm trees. Test 2: Ground Range at 3 mi and Tree Detail gradually increased from 18% towards 100%. At some point the missing local trees pop back into view.
Normally I would say it is some kind of resource limitation, i.e. my 32 bit system can't handle so many polygons. However, the fact that it only happens to the group of eight palm trees, and that the trees pop back into view when I increase Tree Detail (effectively adding even more polygons) suggests to me that maybe there's an outside chance it is a LOD issue with those trees?
