ICE is a state machine running in the background, so you have to wait for each step completion before going to the next one. Here is a sample Console C# app that should work, provided you added at least two valid images (test with the UI first):

class Program
{
    static void Main(string[] args)
    {
        using (var stitch = new StitchEngineWrapper()) // using Microsoft.Research.ICE.Stitching;
        {
            var taskCompleted = new AutoResetEvent(false);
            stitch.ProgressChanged += (s, e) => Console.Write(".");
            stitch.TaskCompleted += (s, e) =>
            {
                Console.WriteLine();
                taskCompleted.Set();
            };

            var pi = new StitchProjectInfo();
            pi.SourceImages.Add(new ImageInfo(@"c:\myPath\lenna1.jpg", null));
            pi.SourceImages.Add(new ImageInfo(@"c:\myPath\lenna2.jpg", null));
            if (!stitch.InitializeFromProjectInfo(pi) || stitch.HasLastError)
            {
                Console.WriteLine("Initialization failed.");
                if (stitch.HasLastError)
                {
                    Console.WriteLine("Error 0x" + stitch.LastError.ToString("x8") + ": " + stitch.LastErrorMessage);
                }
                return;
            }
            Console.WriteLine("Initialization ok.");

            stitch.StartAligning();
            taskCompleted.WaitOne(Timeout.Infinite);
            if (stitch.AlignedCount < 2 || stitch.HasLastError)
            {
                Console.WriteLine("Alignement failed. Wrong input.");
                Console.WriteLine("Error 0x" + stitch.LastError.ToString("x8") + ": " + stitch.LastErrorMessage);
                return;
            }
            Console.WriteLine("Alignement ok.");

            stitch.StartCompositing();
            taskCompleted.WaitOne(Timeout.Infinite);
            if (stitch.HasLastError)
            {
                Console.WriteLine("Composition failed.");
                Console.WriteLine("Error 0x" + stitch.LastError.ToString("x8") + ": " + stitch.LastErrorMessage);
                return;
            }
            Console.WriteLine("Composition ok.");

            stitch.StartProjecting();
            taskCompleted.WaitOne(Timeout.Infinite);
            if (stitch.HasLastError)
            {
                Console.WriteLine("Projection failed.");
                Console.WriteLine("Error 0x" + stitch.LastError.ToString("x8") + ": " + stitch.LastErrorMessage);
                return;
            }
            Console.WriteLine("Projection ok.");

            var options = new OutputOptions(ExportFormat.JPEG, 75, true, false, false);
            stitch.StartExporting(@"c:\myPath\stitched.jpg", stitch.ResetCropRect, 1, options, false);
            taskCompleted.WaitOne(Timeout.Infinite);
            Console.WriteLine("Export ok.");
        }
    }
}

Here is a sample Lenna stiched (note images Y-offset and overlap):

left:

right:

stitched:

Note black artifacts and funny hair on the right due to stitching