WPF UserControl - cannot select TextBox - wpf

Question

I have a really simple WPF UserControl:
<UserControl x:Class="dr.SitecoreCompare.WPF.ConnectionEntry"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Name="connEntry"
BorderBrush="Navy" BorderThickness="1" Margin="5,0,0,5" >
<StackPanel Margin="0,10,0,0" >
<Label FontWeight="ExtraBold" Content="{Binding ElementName=connEntry, Path=Title}"></Label>
<Label Margin="0,5,0,0">Server:</Label>
<TextBox x:Name="txtServer" TabIndex="1" Text="{Binding Path=ServerName}" ></TextBox>
<Label>Database:</Label>
<TextBox x:Name="txtDatabase" TabIndex="2" Text="{Binding Path=DatabaseName}"></TextBox>
</StackPanel>
This is used twice in the same window. Now, I can select the first TextBox on both th instances of my UserControl, but the second ("txtDatabase") textbox cannot be selected, neither by tabbing or clicking. Why is this ? Am I missing something with regards to creating WPF usercontrols ?
EDIT:
DatabaseName is not readonly, it is a simple property. The XAML for the window the usercontrol is placed on looks like this:
<Window x:Class="dr.SitecoreCompare.WPF.ProjectDialog"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:c="clr-namespace:dr.SitecoreCompare.WPF"
Title="Choose project" Height="280" Width="500"
WindowStartupLocation="CenterOwner" WindowStyle="SingleBorderWindow" HorizontalAlignment="Center" ShowInTaskbar="False" ShowActivated="True" ResizeMode="NoResize" VerticalContentAlignment="Top" VerticalAlignment="Center">
<StackPanel>
<Label>Choose databases</Label>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<c:ConnectionEntry Grid.Column="0" x:Name="connMaster" Title="Master:" Padding="5" />
<c:ConnectionEntry Grid.Column="1" x:Name="connSlave" Title="Slave:" Padding="5" />
</Grid>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,0" >
<Button x:Name="btnCancel" Click="btnCancel_Click">Cancel</Button>
<Button x:Name="btnOK" Click="btnOK_Click">OK</Button>
</StackPanel>
</StackPanel>
</Window>

Answer 1

Try Mode=TwoWay in your binding. I've seen this where the initialization sets the value and the control can not set the the value.
<TextBox x:Name="txtDatabase" TabIndex="2" Text="{Binding Path=DatabaseName, Mode=TwoWay}"></TextBox>

Answer 2

This works in XamlPad, so I think there is something outside the code you posted that is causing the problem. Is DatabaseName readonly?