Managing and editing AnalogWaveform

I am using an AnalogWaveform<double> to store a waveform of recorded samples.

I want to run my waveform through an FIR filter to clean it up a little. Here is the function I wrote:

 public static AnalogWaveform<double> FIRFilter(AnalogWaveform<double> Waveform, double [] Coefficients)
        {
            
            AnalogWaveform<double> Result;
            
            NationalInstruments.Analysis.Dsp.Filters.FirDirectFilter MyFilter = new FirDirectFilter(Coefficients);
            double[] InputData = Waveform.GetRawData();
            double[] OutputData = MyFilter.FilterData(InputData);
            Result = new AnalogWaveform<double>(0, Waveform.Capacity);
            Result.Append(OutputData);
            Result.Timing = Waveform.Timing; // I get an exception here, telling me that "The number of irregular time stamps is not equal to the number of samples in the waveform."   
            
            return Result;
        }

I was expecting that I would have something like:

Waveform.Samples = { { 0, 7/16/13 9:22:22.01},  { 0.002, 7/16/13 9:22:22.01}, .....  { 0.3223, 7/16/13  9:22:28.93} }

After the filtering and append I was expecting:

Result.Samples = { { Filtered0},  { Filtered 0.002}, .....  { Filtered 0.3223} }

and after the timing:

Result.Samples = { { Filtered 0, 7/16/13 9:22:22.01},  { Filtered 0.002, 7/16/13 9:22:22.01}, .....  { Filtered 0.3223, 7/16/13  9:22:28.93} }

Can you tell me why I am getting this exception and the "right way" to get what I want? 

2) This is my construction of that waveform:

            _RawSampleWaveform = new AnalogWaveform<double>(0, 0);
            _RawSampleWaveform.Append(new double[] { 0 });
            _RawSampleWaveform.Timing = WaveformTiming.CreateWithIrregularInterval(new DateTime[] { DateTime.Now });

Is there a better way than having a 'fake' 0 sample. If I try to change the timing without that 'fake' sample I get the same exception-- that my number of samples does not match my number of timestamps.

Suggestions on the "right" way to do this appreciated.

Thanks,

Roger