hi great Lego,
the problem is reproposed.
i make a new build today (WT1.4.0.77), with:
#Updates
X:\langpacks\x64\lp_ru-ru.cab
X:\langpacks\x64\lp_de-de.cab
X:\langpacks\x64\lp_es-es.cab
X:\langpacks\x64\lp_fr-fr.cab
X:\langpacks\x64\lp_it-it.cab
X:\AddOn\x64\IE9-win7_x64.msu
the resulted lang.ini is:
[Available UI Languages]
en-US = 3
[Fallback Languages]
en-US = en-us
same in sources and in boot.ini\2\sources\
LP is integreted correctly, i changed the lang without WU.
for serve you,
theSLug
EDIT: testing on WT 1.5.0.1
EDIT2:
same on 1.5.0.1EDIT3: the 1.5.0.1 has a different behavior, what is install pending?

1.5.0.1.png 78.17K
17 downloadsLP files copied in install.wim but not in boot.wim no lang.ini modified.
MOUNT LOGS:
Microsoft Windows Setup (x64)_64605.log
[2352] [ INFO ] Mounting new image.
Wim: [E:\7usab\DVD\SOURCES\boot.wim]
Image Index: [2]
Mount Path: [E:\7toolkit_temp\WinToolkit_TEMP\Boot]
[2352] [ INFO ] Wimserv process started for guid 3133baaf-c443-4a76-8809-0bf2f142be99. Id is 5536
[5536] [ INFO ] ImageUnmarshallHandle: Reconstituting wim at E:\7usab\DVD\SOURCES\boot.wim.
[5536] [ INFO ] Mounted image at E:\7toolkit_temp\WinToolkit_TEMP\Boot.
[5536] [ INFO ] Received unmount request for image with guid 3133baaf-c443-4a76-8809-0bf2f142be99.
[5536] [ INFO ] Unmount for image at E:\7toolkit_temp\WinToolkit_TEMP\Boot complete.
Microsoft Windows Setup (x64)_78334.log
[5704] [ INFO ] ImageUnmarshallHandle: Reconstituting wim at E:\7usab\DVD\SOURCES\boot.wim.
Edited by theSLug, 13 November 2012 - 10:23 AM.