Combobox empty in Windows XP but not in Windows 7 - wpf

Question

I've written this WPF where I have combo boxes that are bound to ObservableCollection objects. When i run the app in Windows 7 the bindings work perfectly and all is good. When i run this in WindowsXP everything looks nice but the drop downs are empty. Anyone have any experience with this and have you fixed it somehow?
Here's XAML for this (part of it):
<StackPanel x:Name="spUnrecRxItems">
<Border BorderBrush="Silver" CornerRadius="3,3,3,3" BorderThickness="0,3,0,0" Height="Auto"
HorizontalAlignment="Left" Margin="23,6,0,0" Width="200" Background="#FFEFEEEE">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBlock Name="tbUR1" Foreground="#FFDE2226" FontSize="14" FontWeight="Bold"
TextWrapping="Wrap" Width="Auto" HorizontalAlignment="Left" FontFamily="Arial" Grid.Row="0"
Margin="10,10,0,0" Text="{Binding DrugName}" />
<TextBlock Foreground="#FF484747" HorizontalAlignment="Left"
Margin="10,0,0,0" FontSize="12" Text="{Binding FillMinMaxDate}" Grid.Row="1" />
<TextBlock Foreground="#FF484747" HorizontalAlignment="Left"
Margin="10,0,0,0" FontSize="12" Text="{Binding PhysiciansName}" Grid.Row="2" />
<TextBlock ForceCursor="False" Foreground="#FF707170" HorizontalAlignment="Left"
Margin="10,0,0,0" Name="tbSourceCount" VerticalAlignment="Top" FontSize="12"
MouseDown="tbSource_MouseDown" Text="{Binding SourceCount, StringFormat=Source ({0})}" Grid.Row="3">
</TextBlock>
</Grid>
</Border>
<Expander x:Name="expManualRec" Background="DarkGray" Width="180" HorizontalAlignment="Center">
<Expander.Header>
<TextBlock HorizontalAlignment="Center" Text="Reconcile" Foreground="White" />
</Expander.Header>
<Grid Height="Auto">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<ComboBox x:Name="cboReconType" HorizontalAlignment="Center" Margin="8 0 0 0" Width="160" Height="Auto" Grid.Row="1"
SelectionChanged="cboReconType_SelectionChanged" ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl}, Path=DataContext.ReconTypes}" />
<ComboBox x:Name="cboRecReason" HorizontalAlignment="Center" Margin="8 0 0 0" Width="160" Height="Auto" Grid.Row="2"
SelectedValue="{Binding code}">
<ComboBox.Style>
<Style TargetType="ComboBox">
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=cboReconType, Path=Text}" Value="Create A Question">
<Setter Property="ComboBox.Visibility" Value="Hidden" />
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=cboReconType, Path=Text}" Value="No Action">
<Setter Property="ComboBox.Visibility" Value="Visible" />
<Setter Property="ItemsSource" Value="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl}, Path=DataContext.ReconReasons}" />
<Setter Property="DisplayMemberPath" Value="description" />
<Setter Property="SelectedValuePath" Value="code" />
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=cboReconType, Path=Text}" Value="Previous Questionnaire">
<Setter Property="ComboBox.Visibility" Value="Visible" />
<Setter Property="ItemsSource" Value="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl}, Path=DataContext.InterviewQuestionnaires}" />
<Setter Property="DisplayMemberPath" Value="QuestionnaireName" />
<Setter Property="SelectedValuePath" Value="interviewquestionnaire_id" />
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=cboReconType, Path=Text}" Value="">
<Setter Property="ComboBox.Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</ComboBox.Style>
</ComboBox>

Answer 1

This might be happening due to some style, It looks like the text foreground color of your combo-boxes becomes white and looks empty.
You should use Snoop to confirm this and find out if any style in your application is setting the Foreground color of combo-box items to some system color or white.

Answer 2

I'm pretty new here with only 8 months experience in my new job in WPF.
I had the same scenario coding in Windows 8, but Windows 7 and XP would not load the list of a ComboBox in my program.
In the end I figured out: I use EF6 to get data from a SQL Server DB, but in that Combobox list, I used SQL (I had some trouble with the tables in EF to update from the DB, and just wanted to make things work, so I used SQL with SQLConnection and SQLCommand.) Now that I made EF do it's thing, the Win7 and WinXP computers are doing things like I planned them too.