[EDIT]: Just deleted my previous settings.xml and tried with fresh one: didn't fix it. As soon as I disable Advanced Lighting it stays greyed out and I can't reenable it.The following entries are disabled for me after upgrading the client today (it all still works in the latest 1.26.8 version):
- Advanced Lighting Model
- Hardware Skinning
- Avatar Cloth
- Terrain Textures Detail
Moving the camera (Alt + Mousemove) is very jaggy too.
Did something important change in the 1.26.9 version that requires a todo on my side?

GPU-Table is the same in both installation folders.
Quality and Performance got set to "High" instead of "Ultra". If I move it to Ultra, I see shadows and all. "Advanced Lighting" is still greyed out and off. But if I close the Preferences and reopen them, Advanced Lighting is enabled, Hardware Skinning and Avatar Cloth . If I now disable it, it is greyed out immediately and I can't reenable it, Hardware Skinning and Avatar Cloth are disabled and greyed out, then, too.
Something's weird here. The graphics preferences page is somewhate inconsistent, too. Right now I see shadows but the Advanced Lighting is not enabled.
Cool VL Viewer 1.26.9 (19) Jul 27 2013 12:46:34 (Cool VL Viewer)
RestrainedLove viewer v2.08.03.29
Second Life Server 13.07.12.278519
CPU: Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz (3500.03 MHz)
Memory: 16340 MB
OS Version: Microsoft Windows 7 64-bit Service Pack 1 (Build 7601)
Memory manager: OS native
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce GTX 680/PCIe/SSE2
Windows Graphics Driver Version: 9.18.0013.2049
OpenGL Version: 4.3.0
libcurl Version: libcurl/7.21.1 OpenSSL/0.9.8q zlib/1.2.5 c-ares/1.7.1
J2C Decoder Version: KDU
Audio Driver Version: FMOD Ex 4.44.18
Qt Webkit Version: 4.7.1 (version number hard-coded)
Packets Lost: 0/3191 (0.0%)
Built with MSVC version 1600
Compile flags used for this build:
-DNDEBUG -DLL_RELEASE=1 -DLL_RELEASE_FOR_DOWNLOAD=1 /O2 /Oi /arch:SSE2 /MD /MP /D_SECURE_SCL=0 /D_HAS_ITERATOR_DEBUGGING=0 /DWIN32 /D_WINDOWS /W3 /EHsc /GR /Oy- /GS /arch:SSE2 /fp:fast /TP /W2 /Zc:forScope /Zc:wchar_t- /c /nologo /DLL_WINDOWS=1 /DDOM_DYNAMIC /DUNICODE /D_UNICODE /DWINVER=0x0501 /D_WIN32_WINNT=0x0501 /DLL_ALLOW_DEFORMER_IN_SL=1 /DLL_USE_OLDFILESTREAMS=1 /DCARES_STATICLIB /DLIB_NDOF=1