Telerik Silverlight RadGridView Issues

I am new to Silverlight RadGridView control from (Q2 2009). I was trying to use a nested RadGridView in the RowDetailsTemplate like below.

Update: With the help of Vlad from Telerik, learned that there is a Service pack released which fixed issues 2 and 3, but scrolling seems to be still slow when compared to the regular DataGrid doing the samething and you see lot of flickering

I am having multiple issues.

<grid:RadGridView   x:Name=”RadGridView1″ ShowGroupPanel=”False”   IsReadOnly=”True”
                          RowIndicatorVisibility=”Collapsed”
                          AutoGenerateColumns=”False”  ColumnsWidthMode=”Fill”
                          RowDetailsVisibilityMode=”Visible”
                           CanUserFreezeColumns=”False” >
            <grid:RadGridView.Columns>
                …
            </grid:RadGridView.Columns>

            <grid:RadGridView.RowDetailsTemplate>
                <DataTemplate>
                    <Grid>
                        <grid:RadGridView  ShowColumnHeaders=”False” ShowGroupPanel=”False”
                                      ItemsSource=”{Binding ChildItems}”    IsReadOnly=”True” 
                                       Visibility=”Visible”
                          AutoGenerateColumns=”False”  ColumnsWidthMode=”Fill”
                          RowDetailsVisibilityMode=”Collapsed”
                           CanUserFreezeColumns=”False” >
                            <grid:RadGridView.Columns>
                                …
                            </grid:RadGridView.Columns>
                        </grid:RadGridView>
                    </Grid>
                </DataTemplate>
            </grid:RadGridView.RowDetailsTemplate>
        </grid:RadGridView>

1. With 10  rows of data. It is just not usable as scrolling takes long time. that is just for starters

2. I dont want to display any RowIndicator for the inner RadGridView. The property  “RowIndicatorVisibility” works correctly when set to “Collapsed” on the outer RadGridView when you add this property to the Inner RadGridView. you dont see any data in the Inner RadGridView

3. When the filter is applied, the inner RadGridView will not display any data

Tried to flatten the hierarchy but the filter functionality would be lost as I dont want to filter on the values of the InnerCollection and I could not find a way to tell dont include some values in the filter popup

If any one has any Ideas or workaround, please let me know

BTW,  the same scenario when using the DataGrid that comes with Silverlight, it seemed to work just fine, except for the ability to filter (out of the box)