title: xsd.exe generates duplicate attributes when run on OFX2 schema
body: <p>Using the command line:</p>
  
  <pre><code>"xsd.exe" "OFX 2.1.1 schema/OFX2_Protocol.xsd" /c /namespace:OFX /nologo"
  </code></pre>
  
  <p>The resulting C# source file fails to build with these errors:</p>
  
  <pre><code>D:\blah\OFX2_Protocol.cs(19,6): error CS0579: Duplicate 'System.CodeDom.Compiler.GeneratedCodeAttribute' attribute
  D:\blah\OFX2_Protocol.cs(20,6): error CS0579: Duplicate 'System.SerializableAttribute' attribute
  D:\blah\OFX2_Protocol.cs(21,6): error CS0579: Duplicate 'System.Diagnostics.DebuggerStepThroughAttribute' attribute
  D:\blah\OFX2_Protocol.cs(22,6): error CS0579: Duplicate 'System.ComponentModel.DesignerCategoryAttribute' attribute
  D:\blah\OFX2_Protocol.cs(23,6): error CS0579: Duplicate 'System.Xml.Serialization.XmlTypeAttribute' attribute
  D:\blah\OFX2_Protocol.cs(24,6): error CS0579: Duplicate 'System.Xml.Serialization.XmlRootAttribute' attribute
  </code></pre>
  
  <p>A similar XSD schema, which I copied from the OFX2 schema then trimmed down to the useful bits that I wanted, generates a C# file which builds just fine, yet has all the same attributes as the full schema's C# representation.</p>
  
  <p>Any idea why? Is the OFX schema broken? Is xsd.exe broken? Is C# broken? Am I broken?</p>