[abenedik]

I cannot reproduce that. Also, I have never got a report of such an issue from any of my customers.

Therefore I would guess that you have a problem with your graphics card drivers or windows system.
Could you please check that and in case of older drivers update them.

If this will not help, please try the following:

1)
You can also try to enable logging warnings to Visual Studio output window. This is done by the following code:

Ab3d.DirectX.DXDiagnostics.LogLevel = Ab3d.DirectX.DXDiagnostics.LogLevels.Warn;
Ab3d.DirectX.DXDiagnostics.IsWritingLogToOutput = true;

Then reproduce the issue and check if there is any line in Visual Studio Output window that starts with "DXEngine" text. This may indicate the cause of the problem.

2)
You may also try to resize the application window - does that helps?

3)
You may also try to use software rendering - run the samples project and in the settings select software rendering.

4)
Run the application on some other computer.