WPF - inherit from System.Windows.Application in VB.NET

[Karol Deland]

I would like to have my own application class that inherits from
System.Windows.Application. The problem is that in the Application.xaml file,
I have to declare the app like this :

<src:MyBaseApplication x:Class="MyApplication"
xmlns:src="clr-namespace:MyApplication;assembly=WpfTestApplication"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="FPrincipal.xaml">
<Application.Resources>

</Application.Resources>
</src:MyBaseApplication>

It works great at runtime, but when I edit the project properties, i receive
the following error message by the project properties editor of Visual Studio
:

An error occurred trying to load the application definition file for this
project. The file '[...]\Application.xaml' could not be parsed. Please edit
the file in the XAML editor to fix the error.

Could not find the expected root element "Application" in the application
definition file.

The project is a VB.NET project. Somebody have a workaround? I want to keep
the application.xaml file.

Thanks