Using the Color Theme Generator application and applying a custom palette for the Windows8 theme, more specifically any of the dark themes, the RadTabControl's tab foreground colors are incorrect. Specifically, they'll be showing as dark text on a dark background - but the foreground text should be light (not dark). Restarting the Color Theme Generator application with this dark color palette as the default, you'd see the problem disappear - until you switch to a light palette (at which point you have the reverse problem).

Clearing and re-merging the theme ResourceDictionaries solves it.

You have the following scenario:

The UpdateValueEvent property is set to "LostFocus". You have bound the Value property of the control to a property from your ViewModel. 


When this property is changed programmatically from negative to positive several times, the Value property of the control isn't updated correctly.

It stays negative when it must stay positive.


Workaround (if applicable):
You can change the UpdateValueEvent property to "PropertyChanged" 

Other Possible workaround (if the bound property is named "Sum")

private void radMaskedNumericInputSum_ValueChanging_1(object sender, Telerik.Windows.Controls.MaskedInput.RadMaskedInputValueChangingEventArgs e)
{
    if (this.Sum != (double)e.NewValue)
    {              
        e.Handled = true;
    }
}

Setting the Background property of RadComboBox no longer changes the background color of the control.

To work this around, you can add a global event handler for the Loaded event of RadComboBox and set the corresponding backgrounds in code.

static MainWindow()
{
	EventManager.RegisterClassHandler(typeof(RadComboBox), RadComboBox.LoadedEvent, new RoutedEventHandler(OnComboBoxLoaded));
}

private static void OnComboBoxLoaded(object sender, RoutedEventArgs e)
{
	var comboBox = (RadComboBox)sender;
	if (!comboBox.IsEditable)
	{
		if (comboBox.IsEnabled)
		{
			var buttonChrome = comboBox.FindChildByType<ButtonChrome>();
			buttonChrome.Background = Brushes.Purple;
		}
		else
		{
			comboBox.Background = Brushes.Purple;
		}                
	}	
}

When a RadGridView cell has a validation error, a red border will appear around the cell. In this case, the top validation border is missing on the first row cells. As a workaround, you can move the ContentPresenters of the cells a little bit in the loaded event of the control.

private void RadGridViewView_Loaded(object sender, System.Windows.RoutedEventArgs e)
{
    var treeListView = sender as RadTreeListView;
    var editorPresenters = treeListView.ChildrenOfType<ContentControl>().Where(x => x.Name == "PART_ContentPresenter" && x.ParentOfType<GridViewCell>() != null);
    foreach (var item in editorPresenters)
    {
        item.Margin = new System.Windows.Thickness(1);
    }
}

Currently large diagrams are hard to export with good quality because of the memory limitation in WritableBitmap when the DPI is increased.

 -- One option is to use BitMapCacheBrush (discussed here http://www.telerik.com/forums/low-resolution-using-exporttoimage-on-big-diagram)

 -- Another option is to export multiple images of the diagram which cover it all. Then possibly combine these pictures into one.

 -- Also , you can try increasing the operating memory of your Visual Studio

Per the thread at "http://www.telerik.com/forums/isexpandablebinding-requires-user-interaction-with-control-to-take-effect" I have modified the IsExpandedRowBinding sample to recreate the problem. I modified the button to expand and collapse the first row. To reproduce the problem:

1. Expand the first row.
2. Scroll down so the first row is not visible but it's children are visible.
3. Press the button. The expected behavior is the first row should collapse but nothing happens.
4. Scroll up so the first row is visible. The first row collapses.