From http://www.noesisengine.com/forums/viewtopic.php?f=3&t=1178

The following XAML causes memory leak. The datacontext object (i.e. the object that provide SomeProperty property) is not released even after UI element is destroyed.

<Grid x:Name="MyGrid" Grid.Row="0" Background="WhiteSmoke" ContextMenuService.PlacementTarget="{Binding ElementName=MyGrid}">
    <Grid.ContextMenu>
        <ContextMenu>
            <MenuItem Header="{Binding SomeProperty}"></MenuItem>
        </ContextMenu>
    </Grid.ContextMenu>
</Grid>

Need to activate the context menu at least once (i.e right-click on the grid) to reproduce the leak.

Memory doesn't leak if I either remove the ContextMenuService.PlacementTarget or the Header="{Binding SomeProperty}".