WPF Visibility attribute designer issue

Question

I've recently started having issues with Visibility attribute at designtime. Everything works fine at runtime but the Visibility attribute has no effect at designtime.

I've reinstalled Visual Studio and the .net framework but the issue persists.

Sample code:

<StackPanel>
        <TextBlock Text="X" Visibility="Collapsed" Background="Red" />
        <TextBlock Text="Y"></TextBlock>
</StackPanel>

At runtime X is collapsed while at designtime it is shown.

Answer 1

Installing VS2010 SP1 fixed the issue. SP can be found at: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=75568aa6-8107-475d-948a-ef22627e57a5