How can I define a VisualState for MouseOver and Focus simultaneously in SL?

Question

Hello,

I have a Silverlight application (3.0) and defined some Visualstates for TextBoxes in it:

                        <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Normal"/>
                            <VisualState x:Name="MouseOver">
                                <Storyboard>
                                    <!--<ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverBorder" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)">
                                        <SplineColorKeyFrame KeyTime="00:00:00" Value="#FFEEEEEE"/>
                                    </ColorAnimationUsingKeyFrames>-->
                                    <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                        <EasingColorKeyFrame KeyTime="00:00:00" Value="#FF878787"/>
                                    </ColorAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="DisabledVisualElement" Storyboard.TargetProperty="Opacity">
                                        <SplineDoubleKeyFrame KeyTime="0" Value="1"/>
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="ReadOnly">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames Storyboard.TargetName="ReadOnlyVisualElement" Storyboard.TargetProperty="Opacity">
                                        <SplineDoubleKeyFrame KeyTime="0" Value="1"/>
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="FocusStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition GeneratedDuration="00:00:00.2000000" To="Focused"/>
                                <VisualTransition From="Focused" GeneratedDuration="00:00:00.2000000"/>
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="Focused">
                                <Storyboard>
                                    <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverBorder" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)">
                                        <EasingColorKeyFrame KeyTime="00:00:00" Value="White"/>
                                    </ColorAnimationUsingKeyFrames>
                                    <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                        <EasingColorKeyFrame KeyTime="00:00:00" Value="#FF7A99C3"/>
                                    </ColorAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverBorder" Storyboard.TargetProperty="(Border.BorderThickness)">
                                        <DiscreteObjectKeyFrame KeyTime="00:00:00">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Thickness>1</Thickness>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="FocusVisualElement" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)">
                                        <EasingColorKeyFrame KeyTime="00:00:00" Value="#FF7A99C3"/>
                                    </ColorAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Unfocused">
                                <Storyboard/>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>

It says for example that the backround color of the textbox shall change to a grey color in MousOver state and that it should get white when focused. But when the the textbox has then focus and I move the mouse over it, the background becomes grey now. How can I tell Silverlight not to change the background when focused?

Thanks, Rocko