Vista - Exception and slow loading when using HwndSource from a VB6 app

Hello,

I am currently playing with WPF and C++/CLI to see how easy it would be to
host a WPF page inside a Visual Basic 6 form. It is working, except that the
application loading time to load a simple XAML file containing only a
<Button> tag is more than 10 seconds.

What I don't understand is that if I call the exact same .NET class library
(Dynacom.Windows.WinFX.dll) from a Visual Basic .NET application, the
loading is instantaneous.

I attached a debugger to the Visual Basic 6 application to look for any
differences with the .NET app during loading. There are some C++ exceptions
that are thrown but I cannot figure out the cause. Here is the call stack
when the exception occurs:

kernel32.dll!_RaiseException@16() + 0x52 bytes
msvcr80.dll!_CxxThrowException(void * pExceptionObject=0x00000000, const
_s__ThrowInfo * pThrowInfo=0x00000000) Line 166 C++
PresentationCore.dll!System.Windows.Media.Composition.DUCE.Channel.Commit()
+ 0x5d bytes
PresentationCore.dll!System.Windows.Media.MediaContext.CreateChannels() +
0x82 bytes
PresentationCore.dll!System.Windows.Media.MediaSystem.ConnectChannels(System.Windows.Media.MediaContext
mc = {System.Windows.Media.MediaContext}) + 0x5e bytes
PresentationCore.dll!System.Windows.Media.MediaContext.MediaContext(System.Windows.Threading.Dispatcher
dispatcher = {System.Windows.Threading.Dispatcher}) + 0x149 bytes
PresentationCore.dll!System.Windows.Media.MediaContext.From(System.Windows.Threading.Dispatcher
dispatcher = {System.Windows.Threading.Dispatcher}) + 0x58 bytes
PresentationCore.dll!System.Windows.Media.MediaContext.RegisterICompositionTarget(System.Windows.Threading.Dispatcher
dispatcher = {System.Windows.Threading.Dispatcher},
System.Windows.Media.ICompositionTarget iv =
{System.Windows.Interop.HwndTarget}) + 0x20 bytes
> PresentationCore.dll!System.Windows.Interop.HwndTarget.HwndTarget(System.IntPtr
> hwnd = 0x00120892) + 0x44c bytes
PresentationCore.dll!System.Windows.Interop.HwndSource.Initialize(System.Windows.Interop.HwndSourceParameters
parameters = {System.Windows.Interop.HwndSourceParameters}) + 0x3a4 bytes
PresentationCore.dll!System.Windows.Interop.HwndSource.HwndSource(System.Windows.Interop.HwndSourceParameters
parameters = {System.Windows.Interop.HwndSourceParameters}) + 0x45 bytes
Dynacom.Windows.WinFX.dll!DynacomWindowsWinFX::WPFHost::Initialize(int
parentWindow = 0x10085e) Line 18 + 0x4d bytes C++

My project is attached to this message. I would like to know if anybody has
experienced this problem and if there's anything I should do to improve
performance.

Thank you!

Gabriel