Help with the Tab Item

I have tried to add a image to the background of the tab item and i have added and now the problem is when we click on the tab item (i.e Home tab) it goes all white the logo disspears and again when i click on another tab item them it goes white and the logo of the previous one gets visible.. here is a sample code for a tab item of mine

<TabItem Header="" Margin="331.5,-2,-413.833,2.334" Height="74.666" VerticalAlignment="Top" Cursor="SizeAll" BorderBrush="{x:Null}" Foreground="{x:Null}" Selector.IsSelected="False">

May be this is a very basic thing but i am a rookie so please advice me how to remove the white thing when i click on the tab item

Thanks