Hi Henri,
I uninstalled both 1.26.4.61 and 1.26.6.18 and then re-installed 1.26.6.18 by itself. Cleared the cache and still experienced the same issue. It seems like the visual portion of the video just isn't updating to the viewer. Audio is present but for some reason or other, the visual does not appear when a video is started that uses the legacy parcel media. Editing the prim seems to make the video visuals appear.
Other than the video issue, the speed to download textures and framerate is un-matched by any other viewer

Attached is an updated log file and screenshots.
Cool VL Viewer 1.26.6 (18) Apr 6 2013 14:58:44 (Cool VL Viewer)
RestrainedLove viewer v2.08.03.29
Release Notes
You are at 286161.4, 279438.4, 26.8 in Bracket located at sim8964.agni.lindenlab.com (216.82.41.140:13000)
Second Life RC LeTigre 13.04.01.273300
Release Notes
CPU: Intel(R) Core(TM)2 CPU 4300 @ 1.80GHz (1795.53 MHz)
Memory: 3008 MB
OS Version: Microsoft Windows XP Service Pack 3 (Build 2600) compatibility mode. real ver: 6.0 (Build 2900)
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce 9400 GT/PCIe/SSE2
Windows Graphics Driver Version: 6.14.0013.1090
OpenGL Version: 3.3.0
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 version 3.750000
Qt Webkit Version: 4.7.1 (version number hard-coded)
Packets Lost: 0/14215 (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_NEW_HTTP_CORE=1 /DCARES_STATICLIB /DCARES_STATICLIB /DLIB_NDOF=1