Virtualisation not changing properties of new visible items

I am currently using a custom Image object(a wrapper around <Image> object) in a listView. The properties of my custom Image object don't change when a new listview item is visible(realised).

For instance if my listview (containing 30 items with different image urls and different text) has 3 items on the first scroll then the 10th item has the same image as the 1st item. The images repeat in the order [1-9][1-9][1-9].... But to my surprise the text is different in all 30 listViewItems.

On debugging I found that the setter for my image object gets called only for the first 9 items. Can somebody shed light on how other system components(System Image/TextBlock working fine) get new element values?

Code snippet of relevant class property:

public sealed partial class CustomImage : UserControl
{

public static readonly DependencyProperty ImageSourceStringProperty = DependencyProperty.Register("ImageSourceString", typeof(string), typeof(CustomImage), new PropertyMetadata(null, new PropertyChangedCallback(ImageSourceStringChanged)));
    public string ImageSourceString
    {
        get { return (string)GetValue(ImageSourceStringProperty); }
        set
        {
            //THIS NEVER GETS HIT FOR ITEMS AFTER 9th ITEM
            SetValue(ImageSourceStringProperty, value);
            //{More code here}
        }
    }
}

Xaml Usage
<ListView ItemsSource="{Binding}">
        <ListView.ItemTemplate>
            <DataTemplate>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="*"/>
                    </Grid.ColumnDefinitions>
                    <custom:customImage x:Name="Img" ImageSourceString="{Binding ImgPath}"/>
                    <TextBlock Grid.Column="1" Text="{Binding Name}"/>
                 </Grid>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>

Am I missing how it is supposed to work? In case something is not clear please let me know, I can clarify.