Mine

Index: System.Security/SecurityElement.cs
===================================================================
--- System.Security/SecurityElement.cs	(revision 88950)
+++ System.Security/SecurityElement.cs	(working copy)
@@ -194,7 +194,7 @@
 							Locale.GetText ("Invalid XML string")
 							+ ": " + value);
 				}
-				text = value;
+				text = Unescape (value);
 			}
 		}
 
@@ -316,6 +316,44 @@
 			return sb.ToString ();
 		}
 
+		private static string Unescape (string str)
+		{
+			StringBuilder sb;
+
+			if (str == null)
+				return null;
+
+			if (str.IndexOfAny (invalid_chars) == -1)
+				return str;
+
+			sb = new StringBuilder ();
+			int len = str.Length;
+			
+			for (int i = 0; i < len; i++) {
+				char c = str [i];
+				if (c == '&') {
+					int end = str.IndexOf (';', i + 1);
+					if (end < 0)
+						// invalid XML
+						throw new ArgumentException (String.Format ("Incomplete entity reference in {0}", str));
+					switch (str.Substring (i, end - i)) {
+					case "lt": sb.Append ('<'); break;
+					case "gt": sb.Append ('>'); break;
+					case "quot": sb.Append ('"'); break;
+					case "apos": sb.Append ('\''); break;
+					case "amp": sb.Append ('&'); break;
+					default:
+						throw new ArgumentException (String.Format ("Cannot resolve entity reference in {0}", str));
+					}
+					i = end; // skip
+				}
+				else
+					sb.Append (c);
+			}
+
+			return sb.ToString ();
+		}
+
 #if NET_2_0
 		public
 #else
Index: Mono.Xml/SecurityParser.cs
===================================================================
--- Mono.Xml/SecurityParser.cs	(revision 88950)
+++ Mono.Xml/SecurityParser.cs	(working copy)
@@ -101,7 +101,7 @@
 
 		public void OnChars (string ch) 
 		{
-			current.Text = ch;
+			current.Text = SecurityElement.Escape (ch);
 		}
 
 		public void OnEndParsing (SmallXmlParser parser) {}
Index: Test/Microsoft.Win32/RegistryKeyTest.cs
===================================================================
--- Test/Microsoft.Win32/RegistryKeyTest.cs	(revision 88950)
+++ Test/Microsoft.Win32/RegistryKeyTest.cs	(working copy)
@@ -2592,6 +2592,26 @@
 			}
 		}
 
+		[Test]
+		public void EscapeRegistryValue () // bug #322839
+		{
+			try {
+				using (RegistryKey createdKey = Registry.CurrentUser.CreateSubKey ("bug322839")) {
+					createdKey.SetValue ("Path", "/usr/lib/whatever");
+					createdKey.SetValue ("Info", "<Great\"News\">!");
+				}
+
+				using (RegistryKey openedKey = Registry.CurrentUser.OpenSubKey ("bug322839")) {
+					string path = openedKey.GetValue ("Path") as string;
+					Assert.AreEqual ("/usr/lib/whatever", path, "#1");
+					string info = openedKey.GetValue ("Info") as string;
+					Assert.AreEqual ("<Great\"News\">!", info, "#2");
+				}
+			} finally {
+				Registry.CurrentUser.DeleteSubKeyTree ("bug322839");
+			}
+		}
+
 		private bool RunningOnUnix {
 			get {
 #if NET_2_0