Multiple channel DAQ problem

[Dotech]

im just trying using DAQ PCI6224  to acquire three channel data with synchronization. when got  the data array from DAQ with only AI1 connection available, the other two arrays  for channel(AI0,AI2)  have the values as well. What could be the problem?  Here is my code via C#

continuousTask = new NationalInstruments.DAQmx.Task();
// Configure the task and create required channels in task
continuousTask.AIChannels.CreateVoltageChannel("Dev1/ai0", "", AITerminalConfiguration.Differential, -10.0, 10.0, AIVoltageUnits.Volts);
continuousTask.AIChannels.CreateVoltageChannel("Dev1/ai1", "", AITerminalConfiguration.Differential, -10.0, 10.0, AIVoltageUnits.Volts);
continuousTask.AIChannels.CreateVoltageChannel("Dev1/ai2", "", AITerminalConfiguration.Differential, -10.0, 10.0, AIVoltageUnits.Volts);

continuousTask.Timing.ConfigureSampleClock("", 30000, SampleClockActiveEdge.Rising, SampleQuantityMode.ContinuousSamples, samplesPerChannel);
continuousTask.Control(TaskAction.Verify);
analogReader = new AnalogMultiChannelReader(continuousTask.Stream);
analogReader.SynchronizeCallbacks = false;
analogCallback = new AsyncCallback(AnalogReadCallback);
// Create a reference (runningTask) to the task running (continuousTask)
runningTask = continuousTask;
analogReader.BeginReadMultiSample(Convert.ToInt32(continuousTask.Timing.SamplesPerChannel), analogCallback, continuousTask);

data1 = analogReader.EndReadMultiSample (ar);

i using the following two files for data acquisition.  Is this the problem ?

National Instruments Analysis Enterprise version is 8.1.20.472

NationalInstruments.DAQmx.dll  version is 15.5.45.109