I have a WPF user control with a number of textboxes, this is hosted on a WPF window. The textboxes are not currently bound but I cannot type into any of them.

I have put a breakpoint in the KeyDown event of one of the textboxes and it hits it fine and I can see the key I pressed.

The textboxes are declared as

 <TextBox Grid.Row="3"
          Grid.Column="4"
          x:Name="PostcodeSearch"
          Style="{StaticResource SearchTextBox}"
          KeyDown="PostcodeSearch_KeyDown"/>

The style is implemented as

<Style x:Key="SearchTextBox"
       TargetType="{x:Type TextBox}">
        <Setter Property="Control.Margin" Value="2"/>
        <Setter Property="Height" Value="20"/>
        <Setter Property="Width" Value="140"/>
        <Setter Property="HorizontalAlignment" Value="Left"/>
    </Style>

I am hoping I have overlooked something obvious.

EDIT: I only added the KeyDown and KeyUp events just to prove that the keys presses were getting through. I do not have any custom functionality.