Help: can't compile the code

Apr 18, 2009 at 3:59 AM
I got the following message:
Error   The tag 'VisualStateManager.VisualStateGroups' does not exist in XML namespace 'clr-namespace:System.Windows;assembly=WPFToolkit'. Line 67 Position 26. C:\Download\IT\WPF\ex12\WPF.Themes\BubbleCreme\Theme.xaml 67 26 WPF.Themes

My WPFToolkit version is 3.5.31016.1 and I am using VS 2008 Express Edition 


Thanks!