diff -r 7ef0f9dc229c -r 89dfad9633b2 Win32Hid.cs
--- a/Win32Hid.cs	Sun Feb 15 12:22:43 2015 +0100
+++ b/Win32Hid.cs	Sun Feb 15 13:30:54 2015 +0100
@@ -243,6 +243,7 @@
 
         /// BOOLEAN->BYTE->unsigned char
         [FieldOffset(3)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
         public bool IsAlias;
 
         /// USHORT->unsigned short
@@ -263,18 +264,22 @@
 
         /// BOOLEAN->BYTE->unsigned char
         [FieldOffset(12)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
         public bool IsRange;
 
         /// BOOLEAN->BYTE->unsigned char
         [FieldOffset(13)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
         public bool IsStringRange;
 
         /// BOOLEAN->BYTE->unsigned char
         [FieldOffset(14)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
         public bool IsDesignatorRange;
 
         /// BOOLEAN->BYTE->unsigned char
         [FieldOffset(15)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
         public bool IsAbsolute;
 
         /// ULONG[10]
@@ -354,93 +359,125 @@
         public ushort Reserved4;
     }
 
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Explicit)]
-    public struct HIDP_VALUE_CAPS_UNION
-    {
 
-        /// 
-        [System.Runtime.InteropServices.FieldOffsetAttribute(0)]
-        public HIDP_VALUE_CAPS_RANGE Range;
-
-        /// 
-        [System.Runtime.InteropServices.FieldOffsetAttribute(0)]
-        public HIDP_VALUE_CAPS_NOT_RANGE NotRange;
-    }
-
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    /// <summary>
+    /// 
+    /// </summary>
+    [StructLayoutAttribute(LayoutKind.Explicit, Pack = 1)]
     public struct HIDP_VALUE_CAPS
     {
 
         /// USAGE->USHORT->unsigned short
+        [FieldOffset(0)]
         public ushort UsagePage;
 
         /// UCHAR->unsigned char
+        [FieldOffset(2)]
         public byte ReportID;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte IsAlias;
+        [FieldOffset(3)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool IsAlias;
 
         /// USHORT->unsigned short
+        [FieldOffset(4)]
         public ushort BitField;
 
         /// USHORT->unsigned short
+        [FieldOffset(6)]
         public ushort LinkCollection;
 
         /// USAGE->USHORT->unsigned short
+        [FieldOffset(8)]
         public ushort LinkUsage;
 
         /// USAGE->USHORT->unsigned short
+        [FieldOffset(10)]
         public ushort LinkUsagePage;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte IsRange;
+        [FieldOffset(12)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool IsRange;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte IsStringRange;
+        [FieldOffset(13)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool IsStringRange;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte IsDesignatorRange;
+        [FieldOffset(14)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool IsDesignatorRange;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte IsAbsolute;
+        [FieldOffset(15)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool IsAbsolute;
 
         /// BOOLEAN->BYTE->unsigned char
-        public byte HasNull;
+        [FieldOffset(16)]
+        [MarshalAsAttribute(UnmanagedType.U1)]
+        public bool HasNull;
 
         /// UCHAR->unsigned char
+        [FieldOffset(17)]
         public byte Reserved;
 
         /// USHORT->unsigned short
+        [FieldOffset(18)]
         public ushort BitSize;
 
         /// USHORT->unsigned short
+        [FieldOffset(20)]
         public ushort ReportCount;
 
         /// USHORT[5]
-        [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst = 5, ArraySubType = System.Runtime.InteropServices.UnmanagedType.U2)]
-        public ushort[] Reserved2;
+        /// We had to use 5 ushorts instead of an array to avoid alignment exception issues.
+        [FieldOffset(22)]
+        public ushort Reserved21;
+        [FieldOffset(24)]
+        public ushort Reserved22;
+        [FieldOffset(26)]
+        public ushort Reserved23;
+        [FieldOffset(28)]
+        public ushort Reserved24;
+        [FieldOffset(30)]
+        public ushort Reserved25;
 
         /// ULONG->unsigned int
+        [FieldOffset(32)]
         public uint UnitsExp;
 
         /// ULONG->unsigned int
+        [FieldOffset(36)]
         public uint Units;
 
         /// LONG->int
+        [FieldOffset(40)]
         public int LogicalMin;
 
         /// LONG->int
+        [FieldOffset(44)]
         public int LogicalMax;
 
         /// LONG->int
+        [FieldOffset(48)]
         public int PhysicalMin;
 
         /// LONG->int
+        [FieldOffset(52)]
         public int PhysicalMax;
 
-        /// 
-        public HIDP_VALUE_CAPS_UNION Union;
+        /// Union Range/NotRange
+        [FieldOffset(56)]
+        public HIDP_VALUE_CAPS_RANGE Range;
+
+        [FieldOffset(56)]
+        public HIDP_VALUE_CAPS_NOT_RANGE NotRange;
     }
+    
 }