Marked the swizzle properties with the XmlIgnoreAttribute.

Source/OpenTK/Math/Vector3.cs

@@ -24,10 +24,13 @@ SOFTWARE.
 
 using System;
 using System.Runtime.InteropServices;
+using System.Xml.Serialization;
 
 namespace OpenTK.Math
 {
-	/// <summary>Represents a 3D vector using three single-precision floating-point numbers.</summary>
+	/// <summary>
+    /// Represents a 3D vector using three single-precision floating-point numbers.
+    /// </summary>
     /// <remarks>
     /// The Vector3 structure is suitable for interoperation with unmanaged code requiring three consecutive floats.
     /// </remarks>
@@ -1009,6 +1012,7 @@ namespace OpenTK.Math
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector2 with the X and Y components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector2 Xy { get { return new Vector2(X, Y); } set { X = value.X; Y = value.Y; } }
 
         #endregion

Source/OpenTK/Math/Vector3h.cs

@@ -26,11 +26,13 @@ using System;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
+using System.Xml.Serialization;
 
 namespace OpenTK.Math
 {
-
+    /// <summary>
-    /// <summary>3-component Vector of the Half type. Occupies 6 Byte total.</summary>
+    /// 3-component Vector of the Half type. Occupies 6 Byte total.
+    /// </summary>
     [Serializable, StructLayout(LayoutKind.Sequential)]
     public struct Vector3h : ISerializable, IEquatable<Vector3h>
     {
@@ -194,6 +196,7 @@ namespace OpenTK.Math
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector2h with the X and Y components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector2h Xy { get { return new Vector2h(X, Y); } set { X = value.X; Y = value.Y; } }
 
         #endregion

Source/OpenTK/Math/Vector4.cs

@@ -24,6 +24,7 @@ SOFTWARE.
 
 using System;
 using System.Runtime.InteropServices;
+using System.Xml.Serialization;
 
 namespace OpenTK.Math
 {
@@ -830,11 +831,13 @@ namespace OpenTK.Math
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector2 with the X and Y components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector2 Xy { get { return new Vector2(X, Y); } set { X = value.X; Y = value.Y; } }
 
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector3 with the X, Y and Z components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector3 Xyz { get { return new Vector3(X, Y, Z); } set { X = value.X; Y = value.Y; Z = value.Z; } }
 
         #endregion

Source/OpenTK/Math/Vector4d.cs

@@ -24,6 +24,7 @@ SOFTWARE.
 
 using System;
 using System.Runtime.InteropServices;
+using System.Xml.Serialization;
 
 namespace OpenTK.Math
 {
@@ -827,11 +828,13 @@ namespace OpenTK.Math
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector2d with the X and Y components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector2d Xy { get { return new Vector2d(X, Y); } set { X = value.X; Y = value.Y; } }
 
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector3d with the X, Y and Z components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector3d Xyz { get { return new Vector3d(X, Y, Z); } set { X = value.X; Y = value.Y; Z = value.Z; } }
 
         #endregion

Source/OpenTK/Math/Vector4h.cs

@@ -26,11 +26,13 @@ using System;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
+using System.Xml.Serialization;
 
 namespace OpenTK.Math
 {
-
+    /// <summary>
-    /// <summary>4-component Vector of the Half type. Occupies 8 Byte total.</summary>
+    /// 4-component Vector of the Half type. Occupies 8 Byte total.
+    /// </summary>
     [Serializable, StructLayout(LayoutKind.Sequential)]
     public struct Vector4h : ISerializable, IEquatable<Vector4h>
     {
@@ -211,11 +213,13 @@ namespace OpenTK.Math
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector2h with the X and Y components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector2h Xy { get { return new Vector2h(X, Y); } set { X = value.X; Y = value.Y; } }
 
         /// <summary>
         /// Gets or sets an OpenTK.Math.Vector3h with the X, Y and Z components of this instance.
         /// </summary>
+        [XmlIgnore]
         public Vector3h Xyz { get { return new Vector3h(X, Y, Z); } set { X = value.X; Y = value.Y; Z = value.Z; } }
 
         #endregion