Bug in themes

Create a textbox multiline, give it a ribbon theme and the caret appears vertically centered. However non ribbon themes appear as expected with caret at top. You can simulate this behaviour by applying texbox style ket and then setting the style to null to see the correct way it should be.

<TextBox AcceptsReturn="True" MaxLines="40" AcceptsTab="True" Margin="4,4,4,4"
Grid.Row="0" Grid.Column="0" Name="NewNoteTextEditor" UndoLimit="0"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" VerticalContentAlignment="Top"/>