Silverlight中RichTextBox的问题

[YCX1985]

窗口中添加了一个RichTextBox，通过RichTextBox.Xaml把内容存入数据库。RichTextBox.Xaml的获得的格式会有两种：
第一种
<Section xml:space="preserve" HasTrailingParagraphBreakOnPaste="False" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"><Paragraph FontSize="11" FontFamily="Portable User Interface" Foreground="#FF000000" FontWeight="Normal" FontStyle="Normal" FontStretch="Normal" CharacterSpacing="0" Typography.AnnotationAlternates="0" Typography.EastAsianExpertForms="False" Typography.EastAsianLanguage="Normal" Typography.EastAsianWidths="Normal" Typography.StandardLigatures="True" Typography.ContextualLigatures="True" Typography.DiscretionaryLigatures="False" Typography.HistoricalLigatures="False" Typography.StandardSwashes="0" Typography.ContextualSwashes="0" Typography.ContextualAlternates="True" Typography.StylisticAlternates="0" Typography.StylisticSet1="False" Typography.StylisticSet2="False" Typography.StylisticSet3="False" Typography.StylisticSet4="False" Typography.StylisticSet5="False" Typography.StylisticSet6="False" Typography.StylisticSet7="False" Typography.StylisticSet8="False" Typography.StylisticSet9="False" Typography.StylisticSet10="False" Typography.StylisticSet11="False" Typography.StylisticSet12="False" Typography.StylisticSet13="False" Typography.StylisticSet14="False" Typography.StylisticSet15="False" Typography.StylisticSet16="False" Typography.StylisticSet17="False" Typography.StylisticSet18="False" Typography.StylisticSet19="False" Typography.StylisticSet20="False" Typography.Capitals="Normal" Typography.CapitalSpacing="False" Typography.Kerning="True" Typography.CaseSensitiveForms="False" Typography.HistoricalForms="False" Typography.Fraction="Normal" Typography.NumeralStyle="Normal" Typography.NumeralAlignment="Normal" Typography.SlashedZero="False" Typography.MathematicalGreek="False" Typography.Variants="Normal" TextOptions.TextHintingMode="Fixed" TextOptions.TextFormattingMode="Ideal" TextOptions.TextRenderingMode="Auto" TextAlignment="Left" LineHeight="0" LineStackingStrategy="MaxHeight">
<Run>输入的字符</Run></Paragraph></Section>
第二种
<Section xml:space="preserve" HasTrailingParagraphBreakOnPaste="False" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"><Paragraph FontSize="11" FontFamily="Portable User Interface" Foreground="#FF000000" FontWeight="Normal" FontStyle="Normal" FontStretch="Normal" TextAlignment="Left">
<Run Text="输入的字符" /></Paragraph></Section>
第一种格式在某些计算机上读出显示的时候会报错，第二种格式没有问题。这是为什么一直不明白哪里整错了？格式是自动生成的。

[wwwljh]

是不是在装有Silverlight5的机器上第一种格式不报错，装低版本的Silverlight上报错啊？