S3 Multi Part Upload Exception

Using the S3-MultiPartAPI i get an exception:

"{"Your proposed upload is smaller than the minimum allowed size"}"

I test this with 2 files 11MB and 7MB. With 1MB it works without problems.

FileStream fs = new FileStream(foo, FileAccess.ReadWrite);

fs.CopyTo(new S3Tools.S3CopyMemoryStream("bar", new byte[Buffersize + Buffersize/2], transferUtility));

And i set the configuration utilityConfig.MinSizeBeforePartUpload to 2.

public class S3CopyMemoryStream : MemoryStream
    {
        private string _key;
        private byte[] _buffer;
        private S3TransferUtility _transferUtility;
        public StartUploadS3CopyFileStreamEvent StartUploadS3FileStreamEvent { get; set; }

        public int WriteCount { get; private set; }
        public bool EndOfPart { get; private set; }
        public bool InitiatingPart { get; private set; }
        public string UploadPartId { get; set; }
        public List<PartETag> PartETagCollection { get; set; }

        public S3CopyMemoryStream WithS3CopyFileStreamEvent(StartUploadS3CopyFileStreamEvent doing)
        {
            S3CopyMemoryStream s3CopyStream = new S3CopyMemoryStream(this._key, this._buffer, this._transferUtility);

            s3CopyStream.StartUploadS3FileStreamEvent = new S3CopyMemoryStream.StartUploadS3CopyFileStreamEvent(CreateMultiPartS3Blob);

            return s3CopyStream;
        }

        public S3CopyMemoryStream(string key, byte[] buffer, S3TransferUtility transferUtility)
            : base(buffer)
        {
            InitiatingPart = true;
            EndOfPart = false;
            WriteCount = 1;
            PartETagCollection = new List<PartETag>();
            QueueWithIncompleteParts = new Queue<int>();

            _buffer = buffer;
            _key = key;
            _transferUtility = transferUtility;
        }

        public delegate void StartUploadS3CopyFileStreamEvent(S3TransferUtility transferUtility, string key, S3CopyMemoryStream stream);          

        public override bool CanSeek
        {
            get { return false; }
        }

        public override void Write(byte[] array, int offset, int count)
        {
            base.Write(array, offset, count);

            if(Position >= Buffersize)
            {
                if (WriteCount > 1)
                    InitiatingPart = false;
                StartUploadS3FileStreamEvent.Invoke(_transferUtility, _key, this);

                WriteCount++;
                base.Flush();
                base.Seek(0, SeekOrigin.Begin);
                base.Flush();

            }              
        }

        public override void Close()
        {
            if(WriteCount > 1)
                InitiatingPart = false;

            EndOfPart = true;
            StartUploadS3FileStreamEvent.Invoke(_transferUtility, _key, this);
            base.Close();
        }

    }

This is the Uploadevent. In this line i get the exception.

CompleteMultipartUploadResponse completeMultipartUploadResponse = transferUtility.S3Client.CompleteMultipartUpload(completeMultipartUploadRequest);

 static internal void CreateMultiPartS3Blob(S3TransferUtility transferUtility, string key, S3CopyMemoryStream stream)
    {

        if (stream.InitiatingPart)
        {
            InitiateMultipartUploadRequest initiateMultipartUploadRequest =
                new InitiateMultipartUploadRequest()
                    .WithBucketName(transferUtility.BucketName)
                    .WithKey(key);


            InitiateMultipartUploadResponse initiateResponse =
                transferUtility.S3Client.InitiateMultipartUpload(initiateMultipartUploadRequest);
            stream.UploadPartId = initiateResponse.UploadId;

        }


            UploadPartRequest uploadPartRequest =
                new UploadPartRequest()
                    .WithBucketName(transferUtility.BucketName)
                    .WithKey(key)
                    .WithPartNumber(stream.WriteCount)
                    .WithPartSize(stream.Position)
                    .WithUploadId(stream.UploadPartId)
                    .WithInputStream(stream) as UploadPartRequest;

            UploadPartResponse response = transferUtility.S3Client.UploadPart(uploadPartRequest);
            PartETag etag = new PartETag(response.PartNumber, response.ETag);
            stream.PartETagCollection.Add(etag);



        if (stream.EndOfPart)
        {

            CompleteMultipartUploadRequest completeMultipartUploadRequest =
                new CompleteMultipartUploadRequest()
                    .WithBucketName(transferUtility.BucketName)
                    .WithKey(key)
                    .WithPartETags(stream.PartETagCollection)
                    .WithUploadId(stream.UploadPartId);

            CompleteMultipartUploadResponse completeMultipartUploadResponse =
                transferUtility.S3Client.CompleteMultipartUpload(completeMultipartUploadRequest);
            string loc = completeMultipartUploadResponse.Location;

        }

    }

Any suggestions what the problem is?

The Request uses the stream from the current position so i have to set the position to zero before uploading.

First think than post .. *g

greetings