diff --git a/NTwain/Data/TwainValues.cs b/NTwain/Data/TwainValues.cs
index 6fa7c37..11d599d 100644
--- a/NTwain/Data/TwainValues.cs
+++ b/NTwain/Data/TwainValues.cs
@@ -2056,7 +2056,20 @@ namespace NTwain.Data
         Constrainable = 0x40,
         GetHelp = 0x100,
         GetLabel = 0x200,
-        GetLabelEnum = 0x400
+        GetLabelEnum = 0x400,
+
+        /// <summary>
+        /// Cap applies to entire session/machine.
+        /// </summary>
+        Machine = 0x1000,
+        /// <summary>
+        /// Cap applies to bitonal cameras.
+        /// </summary>
+        Bitonal = 0x2000,
+        /// <summary>
+        /// Cap applies to color cameras.
+        /// </summary>
+        Color = 0x4000
     }
 
     /// <summary>
diff --git a/NTwain/Internals/TransferLogic.cs b/NTwain/Internals/TransferLogic.cs
index 8bb93a4..acff1bb 100644
--- a/NTwain/Internals/TransferLogic.cs
+++ b/NTwain/Internals/TransferLogic.cs
@@ -70,7 +70,15 @@ namespace NTwain.Internals
                     if (xferGroup == DataGroups.None ||
                         (xferGroup & DataGroups.Image) == DataGroups.Image)
                     {
-                        var mech = session.CurrentSource.CapGetCurrent(CapabilityId.ICapXferMech).ConvertToEnum<XferMech>();
+                        // default to memory
+                        var mech = XferMech.Memory;
+
+                        object mechRaw = session.CurrentSource.CapGetCurrent(CapabilityId.ICapXferMech);
+                        if (mechRaw != null)
+                        {
+                            mech = mechRaw.ConvertToEnum<XferMech>();
+                        }
+
                         switch (mech)
                         {
                             case XferMech.Memory:
@@ -110,9 +118,13 @@ namespace NTwain.Internals
 
             } while (rc == ReturnCode.Success && pending.Count != 0);
 
-            session.ChangeState(5, true);
-            session.DisableSource();
-
+            // some poorly written scanner drivers return failure on EndXfer so also check for pending count now
+            // this may break with other sources but we'll see
+            if (pending.Count == 0)
+            {
+                session.ChangeState(5, true);
+                session.DisableSource();
+            }
         }
 
         #region audio xfers
diff --git a/NTwain/Properties/VersionInfo.cs b/NTwain/Properties/VersionInfo.cs
index 183c8b0..2f2ce7b 100644
--- a/NTwain/Properties/VersionInfo.cs
+++ b/NTwain/Properties/VersionInfo.cs
@@ -14,6 +14,6 @@ namespace NTwain
         // keep this same in majors releases
         public const string Release = "2.0.0.0";
         // change this for each nuget release
-        public const string Build = "2.0.1";
+        public const string Build = "2.0.3";
     }
 }
\ No newline at end of file
diff --git a/NTwain/Triplets/DGImage/DGImage.ImageMemFileXfer.cs b/NTwain/Triplets/DGImage/DGImage.ImageMemFileXfer.cs
index f1e8a37..5cec36a 100644
--- a/NTwain/Triplets/DGImage/DGImage.ImageMemFileXfer.cs
+++ b/NTwain/Triplets/DGImage/DGImage.ImageMemFileXfer.cs
@@ -15,7 +15,7 @@ namespace NTwain.Triplets
 		/// <returns></returns>
 		public ReturnCode Get(TWImageMemXfer xfer)
 		{
-			Session.VerifyState(6, 6, DataGroups.Image, DataArgumentType.ImageMemFileXfer, Message.Get);
+			Session.VerifyState(6, 7, DataGroups.Image, DataArgumentType.ImageMemFileXfer, Message.Get);
 			return Dsm.DsmEntry(Session.AppId, Session.CurrentSource.Identity, Message.Get, xfer);
 		}
 
diff --git a/NTwain/TwainSource.cs b/NTwain/TwainSource.cs
index 54114a3..b9b2736 100644
--- a/NTwain/TwainSource.cs
+++ b/NTwain/TwainSource.cs
@@ -15,7 +15,7 @@ namespace NTwain
     /// <summary>
     /// Represents a TWAIN data source.
     /// </summary>
-    public partial class TwainSource : INotifyPropertyChanged
+    public partial class TwainSource
     {
         ITwainSessionInternal _session;
 
@@ -179,7 +179,7 @@ namespace NTwain
             private set
             {
                 _supportedCaps = value;
-                OnPropertyChanged("SupportedCaps");
+                //OnPropertyChanged("SupportedCaps");
             }
         }
 
@@ -219,41 +219,82 @@ namespace NTwain
 
         #endregion
 
-        #region INotifyPropertyChanged Members
+        //#region INotifyPropertyChanged Members
+
+        ///// <summary>
+        ///// Occurs when a property value changes.
+        ///// </summary>
+        //public event PropertyChangedEventHandler PropertyChanged;
+
+        ///// <summary>
+        ///// Raises the <see cref="PropertyChanged"/> event.
+        ///// </summary>
+        ///// <param name="propertyName">Name of the property.</param>
+        //protected void OnPropertyChanged(string propertyName)
+        //{
+        //    var syncer = _session.SynchronizationContext;
+        //    if (syncer == null)
+        //    {
+        //        try
+        //        {
+        //            var hand = PropertyChanged;
+        //            if (hand != null) { hand(this, new PropertyChangedEventArgs(propertyName)); }
+        //        }
+        //        catch { }
+        //    }
+        //    else
+        //    {
+        //        syncer.Post(o =>
+        //        {
+        //            try
+        //            {
+        //                var hand = PropertyChanged;
+        //                if (hand != null) { hand(this, new PropertyChangedEventArgs(propertyName)); }
+        //            }
+        //            catch { }
+        //        }, null);
+        //    }
+        //}
+
+        //#endregion
+
+        #region cameras
 
         /// <summary>
-        /// Occurs when a property value changes.
+        /// Gets the cameras supported by the source.
         /// </summary>
-        public event PropertyChangedEventHandler PropertyChanged;
-
-        /// <summary>
-        /// Raises the <see cref="PropertyChanged"/> event.
-        /// </summary>
-        /// <param name="propertyName">Name of the property.</param>
-        protected void OnPropertyChanged(string propertyName)
+        /// <returns></returns>
+        public IList<string> GetCameras()
         {
-            var syncer = _session.SynchronizationContext;
-            if (syncer == null)
+            TWFileSystem fs = new TWFileSystem();
+            List<string> cams = new List<string>();
+            var rc = DGControl.FileSystem.GetFirstFile(fs);
+            while (rc == ReturnCode.Success)
             {
-                try
+                switch (fs.FileType)
                 {
-                    var hand = PropertyChanged;
-                    if (hand != null) { hand(this, new PropertyChangedEventArgs(propertyName)); }
+                    case FileType.Camera:
+                    case FileType.CameraBottom:
+                    case FileType.CameraTop:
+                    case FileType.CameraPreview:
+                        cams.Add(fs.OutputName);
+                        break;
                 }
-                catch { }
-            }
-            else
-            {
-                syncer.Post(o =>
-                {
-                    try
-                    {
-                        var hand = PropertyChanged;
-                        if (hand != null) { hand(this, new PropertyChangedEventArgs(propertyName)); }
-                    }
-                    catch { }
-                }, null);
+                rc = DGControl.FileSystem.GetNextFile(fs);
             }
+            return cams;
+        }
+
+        /// <summary>
+        /// Sets the target camera for cap negotiation that can be set per camera.
+        /// </summary>
+        /// <param name="cameraName"></param>
+        /// <returns></returns>
+        public ReturnCode SetCamera(string cameraName)
+        {
+            TWFileSystem fs = new TWFileSystem();
+            fs.InputName = cameraName;
+            return DGControl.FileSystem.ChangeDirectory(fs);
         }
 
         #endregion
diff --git a/Tests/Tester.Winform/TestForm.cs b/Tests/Tester.Winform/TestForm.cs
index 74050bb..bebe5f1 100644
--- a/Tests/Tester.Winform/TestForm.cs
+++ b/Tests/Tester.Winform/TestForm.cs
@@ -105,19 +105,22 @@ namespace Tester.Winform
 
         private void CleanupTwain()
         {
-            if (_twain.State == 4)
+            if (_twain != null)
             {
-                _twain.CurrentSource.Close();
-            }
-            if (_twain.State == 3)
-            {
-                _twain.Close();
-            }
+                if (_twain.State == 4)
+                {
+                    _twain.CurrentSource.Close();
+                }
+                if (_twain.State == 3)
+                {
+                    _twain.Close();
+                }
 
-            if (_twain.State > 2)
-            {
-                // normal close down didn't work, do hard kill
-                _twain.ForceStepDown(2);
+                if (_twain.State > 2)
+                {
+                    // normal close down didn't work, do hard kill
+                    _twain.ForceStepDown(2);
+                }
             }
         }