http://www.thewitcher.com/community/entry/236
Version 3.1 Corrections/Amendments (18th May 2012)
1.Fixed the display of inter-chapter movies in aspect ratios other than 16:9.
2.Fixed bugs causing the application to close while opening the credits.
3.Relevant Aspect Ratio options are shown in the Configurator.exe if nVidia Surround is supported.
4.Game saves from Act 2 created on older versions of the game are now compatible with the Enhanced Edition, which fixes the dwarven mechanism in Vergen.
5.Added a fix for .NET Framework 4-related issues for the Steam users.