XamlParseException Cannot find source for binding with reference (BindingExpression:Path=IsPinned)

I have the following exception popping up from time to time when I scroll fast or use sliders in RadGridView.

Exception: Exception thrown: 'System.Xaml.XamlParseException' in #####.exe

("Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='Telerik.Windows.Controls.GridView.GridViewRow', AncestorLevel='1''. BindingExpression:Path=IsPinned; DataItem=null; target element is 'GridViewPinButton' (Name=''); target property is 'IsPinned' (type 'Boolean')"). Exception thrown: 'System.Xaml.XamlParseException' in #####.exe ("Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='Telerik.Windows.Controls.GridView.GridViewRow', AncestorLevel='1''. BindingExpression:Path=IsPinned; DataItem=null; target element is 'GridViewPinButton' (Name=''); target property is 'IsPinned' (type 'Boolean')") 80.33s  [15528] <No Name>

I simply host RadGridView in UserControl:

    <telerik:RadGridView ItemsSource="{Binding #######}"
                         IsReadOnly="True"
                         RowIndicatorVisibility="Collapsed"
                         AutoGenerateColumns="False"
                         ShowGroupPanel="False"
                         GridLinesVisibility="Both"
                         ClipboardCopyMode="All"
                         SelectionMode="Extended"
                         FrozenColumnCount="1"
                         CanUserFreezeColumns="False"
                         Background="Transparent"
    >
        <telerik:RadGridView.Columns>

....