* This is just with the 1.26.4 version and all of its current updates for this month.*
And there's a flicker, every 5 to 10 seconds, coming from the other directions, N, S, E.
I did a search about "flicker" here and my trees are perfect, btw, and so is your most excellent 1.26.5 which I am running also, on Low Graphics, for my evolving SL enjoyment.

(I do a lot of work around SL's BB Group, Builder's Brewery. And I am hopeful that your 1.26.4 will come to the "rescue" for those folks needing a much smaller viewer, maybe a bit like a V1.23.5+mesh "Volks Viewer?" with just enough "needful extras" from V2 and V3, so they can still have some advanced fun and to basically "survive" within this crazy little 3d world.
* Required system details with no fancy graphics card below. *
( And this is about like a new laptop, perhaps? )
"Cool VL Viewer 1.26.4 (35) Oct 21 2012 17:52:52 (Cool VL Viewer)
CPU: Pentium(R) Dual-Core CPU E5800 @ 3.20GHz (3200.04 MHz) Memory: 4062 MB
OS Version: Microsoft Windows 7 64-bit Service Pack 1 (Build 7601)
Graphics Card Vendor: Intel Graphics Card: Intel(R) G41 Express Chip set Windows Graphics Driver Version: 8.15.0010.2226 OpenGL Version: 2.1.0 - Build 8.15.10.2226"