Here is a list of Language Pack (LP, a.k.a. MUI) hotfixes:

Caution:  Before installing any hotfixes in production, you should test on a test environment.

 

Post RTM hotfixes specific to LP (MUI):
============================================

935509 A software update is available for versions of Windows Vista that include the Windows BitLocker Drive Encryption feature
http://support.microsoft.com/?id=935509

937287 A software update is available for the Windows Vista installation software feature
http://support.microsoft.com/?id=937287

938371 A software update is available for the Windows Vista installation components
http://support.microsoft.com/?id=938371

Side reading:
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934538 You cannot turn on an optional feature, install a Windows update, install a hotfix, or install a language pack on a Windows Vista-based computer
http://support.microsoft.com/?id=934538

948343 Windows Vista and Windows Server 2008 service packs are not available for installation through Windows Update
http://support.microsoft.com/?id=948343

950376 You cannot upgrade a Windows-based operating system when you have Windows PowerShell 1.0 installed
http://support.microsoft.com/?id=950376

Post Service Pack 1 hotfixes specific to LP (MUI):
============================================

955430 Description of the Windows Vista and Windows Server 2008 installation software feature update released April 28, 2009
http://support.microsoft.com/?id=955430

948465 Information about Service Pack 2 for Windows Vista and for Windows Server 2008 (Preferred)
http://support.microsoft.com/?id=948465

Note:  For Windows Vista Ultimate machines that have all the LP’s installed, you want to install the ones that state ALL Language:

Windows Server 2008 Service Pack 2 and Windows Vista Service Pack 2  - ALL Language Standalone (KB948465)
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=891ab806-2431-4d00-afa3-99ff6f22448d
ISO:
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=f25f9c49-1a3a-4336-ade6-32e34a448608

Windows Server 2008 Service Pack 2 and Windows Vista Service Pack 2 - ALL Language Standalone for x64-based Systems (KB948465)
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=8ad69826-03d4-488c-8f26-074800c55bc3

Windows Server 2008 Service Pack 2 - ALL Language Standalone for ia64-based Systems (KB948465)
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=72293ccd-1bf3-4f67-bb97-2f195198af44

or

932243 The updates that you apply to a Multilingual User Interface (MUI) Language Pack are lost when you restart a computer that is running Windows Vista
http://support.microsoft.com/?id=932243
Langcleanupsysprepaction.dll, Lpksetup.exe , Lpremove.exe, Muilanguagecleanup.dll, Rescinst.dll

938952 The Chinese (Traditional) Language Pack is described as "Chinese (Hong Kong S.A.R.)" on a Windows Vista-based computer
http://support.microsoft.com/?id=938952
Updates Intl.cpl, Langcleanupsysprepaction.dll, Lpksetup.exe, Lpremove.exe, Muilanguagecleanup.dll.

940894 Two identical Catalan entries are listed for the language selection on the first page of the Out Of Box Experience (OOBE) Wizard on a Windows Vista-based computer
http://support.microsoft.com/?id=940894
Updates Msoobe.exe, Msoobe.jpg

941277 The wrong time zone may be applied after you select a time zone on a Windows Vista-based computer that has the Croatian Language Pack installed
http://support.microsoft.com/?id=941277
Updates Timedate.cpl

941698 The wrong language is applied when you restart a Windows Vista-based computer after you run the Out Of Box Experience (OOBE) Wizard
http://support.microsoft.com/?id=941698
Updates Ntoskrnl.exe

942900 A file is not overwritten when you try to overwrite the file by using copy in the command shell on a Windows Vista-based computer that has Italian Language Pack installed
http://support.microsoft.com/?id=942900
Updates Cmd.exe

947506 A hotfix is available to reinstall a corrupted language pack and to resolve the problems that are caused by a corrupted language pack on a Windows Vista-based computer
http://support.microsoft.com/?id=947506
Updates Fixlps.exe

953407 A Group Policy "Documents" setting is localized incorrectly as "Recently used files" on a computer that is running a Japanese version of Windows Server 2008 or of Windows Vista
http://support.microsoft.com/?id=953407
Updates Fde.dll.mui

959441 The "GetFileVersionInfo" function for localized binary files may return incorrect file-version information in Windows Server 2008 and in Windows Vista Service Pack 1
http://support.microsoft.com/?id=959441
Updates Acres.dll, Sysmain.sdb, Acgenral.dll

967584 Two options are missing on the shortcut menu that is opened from the Bluetooth Agent icon if you use an Arabic Language Pack that is preinstalled on your Windows Vista-based computer
http://support.microsoft.com/?id=967584
Updates Bth.inf_loc, Bthport.sys.mui, Fsquirt.exe.mui

971734 Locale data is missing in the saved event logs if you archive the event logs on a computer that is running Windows Vista or Windows Server 2008 and that has an MUI for a non-English language installed
http://support.microsoft.com/?id=971734
Updates Wevtsvc.dll

Side reading:
-------------
939289 The "<servicing>" section of the Autounattend.xml answer file is not processed when Windows Setup automatically identifies the file in Windows Vista
http://support.microsoft.com/?id=939289

Post Service Pack 2 hotfixes specific to LP(MUI):
============================================
971101 Error message when you try to input Korean characters in any search box on a 64-bit Itanium-based computer that runs Windows Server 2008 SP2: "Windows Explorer has encountered a problem and needs to close."
http://support.microsoft.com/?id=971101
Updates Korwbrkr.dll

971734 Locale data is missing in the saved event logs if you archive the event logs on a computer that is running Windows Vista or Windows Server 2008 and that has an MUI for a non-English language installed
http://support.microsoft.com/?id=971734
Updates Wevtsvc.dll

973020 An option in the Web Restrictions settings is localized incorrectly in the Simplified Chinese version of Windows Vista
http://support.microsoft.com/?id=973020
Updates Wpccpl.dll, Wpccpl.dll.mui