Created Unassigned: Using Toolkit and ILMerge [22367]

I am trying to merge Xceed.Wpf.Toolkit.dll to a simple exe file. Everything that I do is failing. I am trying to run the tool from the command line. I have tried the following:

ilmerge /targetplatform:v4,"%ProgramFiles%\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0" "C:\Program Files (x86)\Microsoft\ILMerge\myproject.exe" "C:\Program Files (x86)\Microsoft\ILMerge\Xceed.Wpf.Toolkit.dll" /closed /out:"C:\Users\MyName\Desktop\PlaceEXEHere\MergedFile.exe" /target:winexe /ndebug ---- this gives error ERROR!!: Duplicate type 'XamlGeneratedNamespace.GeneratedInternalTypeHelper' found in assembly 'Xceed.Wpf.Toolkit'

Then I tried

ilmerge /targetplatform:v4,"%ProgramFiles%\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0" "C:\Program Files (x86)\Microsoft\ILMerge\myproject.exe" "C:\Program Files (x86)\Microsoft\ILMerge\Xceed.Wpf.Toolkit.dll" /closed /union /out:"C:\Users\MyName\Desktop\PlaceEXEHere\MergedFile.exe" /target:winexe /ndebug ---- this gives error The assembly 'Xceed.Wpf.Toolkit' was not merged in correctly

what am I doing wrong? Any suggestions? Thanks in advance