SL3 Grid RowDefinition Height Problem

I have a parent grid that contains multiple row definitions, all of which have their height set to 'auto'.

Within the parent grid are individual grids - each individual grid contains a custom content control.

When the custom content control loads, the height may increase. What I am noticing is that when the height does increase, the content overlaps with the content in other rows.

I have specified the horizontal and vertical alignments - am I missing something?

Here is an example:

<Grid x:Name="LayoutRoot">
    <Grid x:Name="ParentGrid>">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid Grid.Row="0">
            <CustomContentControl/>
        </Grid>
        <Grid Grid.Row="1">
            <CustomContentControl/>
        </Grid>
        <Grid Grid.Row="2">
            <CustomContentControl/>
        </G开发者_运维知识库rid>
    </Grid>
</Grid>

I could be that your custom controls do not handle the following overrides correctly:

protected override Size MeasureOverride(Size constraint)

protected override Size ArrangeOverride(Size arrangeSize)

Jim