diff --git a/Bson/Serialization/BsonClassMapSerializer.cs b/Bson/Serialization/BsonClassMapSerializer.cs
index e639bdcfb2..0bedd63234 100755
--- a/Bson/Serialization/BsonClassMapSerializer.cs
+++ b/Bson/Serialization/BsonClassMapSerializer.cs
@@ -108,7 +108,7 @@ namespace MongoDB.Bson.Serialization {
 
                 var classMap = BsonClassMap.LookupClassMap(actualType);
                 if (classMap.IsAnonymous) {
-                    throw new InvalidOperationException("Anonymous class cannot be deserialized.");
+                    throw new InvalidOperationException("An anonymous class cannot be deserialized.");
                 }
                 var obj = classMap.CreateInstance();
 
@@ -132,7 +132,7 @@ namespace MongoDB.Bson.Serialization {
                         } else if (classMap.IgnoreExtraElements) {
                             bsonReader.SkipValue();
                         } else {
-                            string message = string.Format("Unexpected element '{0}'.", elementName);
+                            var message = string.Format("Element '{0}' does not match any field or property of class {1}.", elementName, classMap.ClassType.FullName);
                             throw new FileFormatException(message);
                         }
                     }
@@ -141,7 +141,8 @@ namespace MongoDB.Bson.Serialization {
 
                 foreach (var memberMap in missingElementMemberMaps) {
                     if (memberMap.IsRequired) {
-                        var message = string.Format("Required element '{0}' is missing.", memberMap.ElementName);
+                        var fieldOrProperty = (memberMap.MemberInfo.MemberType == MemberTypes.Field) ? "field" : "property";
+                        var message = string.Format("Required element '{0}' for {1} '{2}' of class {3} is missing.", memberMap.ElementName, fieldOrProperty, memberMap.MemberName, classMap.ClassType.FullName);
                         throw new FileFormatException(message);
                     }
 
@@ -257,7 +258,7 @@ namespace MongoDB.Bson.Serialization {
         ) {
             var documentType = document.GetType();
             if (documentType.IsValueType) {
-                var message = string.Format("SetDocumentId cannot be used with value type '{0}'.", documentType.FullName);
+                var message = string.Format("SetDocumentId cannot be used with value type {0}.", documentType.FullName);
                 throw new BsonSerializationException(message);
             }
 
@@ -266,7 +267,7 @@ namespace MongoDB.Bson.Serialization {
             if (idMemberMap != null) {
                 idMemberMap.Setter(document, id);
             } else {
-                var message = string.Format("Class {0} has no Id member.", document.GetType());
+                var message = string.Format("Class {0} has no Id member.", document.GetType().FullName);
                 throw new InvalidOperationException(message);
             }
         }
diff --git a/BsonUnitTests/BsonUnitTests.csproj b/BsonUnitTests/BsonUnitTests.csproj
index 4d519a2faa..fd1670af66 100644
--- a/BsonUnitTests/BsonUnitTests.csproj
+++ b/BsonUnitTests/BsonUnitTests.csproj
@@ -125,6 +125,7 @@
     <Compile Include="Jira\CSharp239Tests.cs" />
     <Compile Include="Jira\CSharp260Tests.cs" />
     <Compile Include="Jira\CSharp261Tests.cs" />
+    <Compile Include="Jira\CSharp270Tests.cs" />
     <Compile Include="Jira\CSharp70Tests.cs" />
     <Compile Include="Jira\CSharp71Tests.cs" />
     <Compile Include="Jira\CSharp74Tests.cs" />
diff --git a/BsonUnitTests/Jira/CSharp270Tests.cs b/BsonUnitTests/Jira/CSharp270Tests.cs
new file mode 100644
index 0000000000..c513b8e6f0
--- /dev/null
+++ b/BsonUnitTests/Jira/CSharp270Tests.cs
@@ -0,0 +1,75 @@
+/* Copyright 2010-2011 10gen Inc.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using NUnit.Framework;
+
+using MongoDB.Bson;
+using MongoDB.Bson.IO;
+using MongoDB.Bson.Serialization;
+using MongoDB.Bson.Serialization.Attributes;
+
+namespace MongoDB.BsonUnitTests.Jira.CSharp270 {
+    public class C {
+        public ObjectId Id;
+        [BsonRequired]
+        [BsonElement("field")]
+        public int Field;
+        [BsonRequired]
+        [BsonElement("property")]
+        public int Property { get; set; }
+    }
+
+    [TestFixture]
+    public class CSharp270Tests {
+        [Test]
+        public void TestBogusElement() {
+            var document = new BsonDocument("bogus", 0);
+            var message = "Element 'bogus' does not match any field or property of class MongoDB.BsonUnitTests.Jira.CSharp270.C.";
+            var ex = Assert.Throws<FileFormatException>(() => { BsonSerializer.Deserialize<C>(document); });
+            Assert.AreEqual(message, ex.Message);
+        }
+
+        [Test]
+        public void TestMissingElementForField() {
+            var document = new BsonDocument {
+                { "_id", ObjectId.GenerateNewId() },
+                { "property", 0 }
+            };
+            var message = "Required element 'field' for field 'Field' of class MongoDB.BsonUnitTests.Jira.CSharp270.C is missing.";
+            var ex = Assert.Throws<FileFormatException>(() => { BsonSerializer.Deserialize<C>(document); });
+            Assert.AreEqual(message, ex.Message);
+        }
+
+        [Test]
+        public void TestMissingElementForProperty() {
+            var document = new BsonDocument {
+                { "_id", ObjectId.GenerateNewId() },
+                { "field", 0 }
+            };
+            var message = "Required element 'property' for property 'Property' of class MongoDB.BsonUnitTests.Jira.CSharp270.C is missing.";
+            var ex = Assert.Throws<FileFormatException>(() => { BsonSerializer.Deserialize<C>(document); });
+            Assert.AreEqual(message, ex.Message);
+        }
+    }
+}