Error on ReadSingleSampleInt32

Hello--

I'm having an issue where a ReadSingleSampleInt32 call results in an error.  Some background:

I have a counter which counts pulses.  It gets initialized/started as follows:

CountPulseTask = New Task()
CountPulseTask.CIChannels.CreateCountEdgesChannel("/" & DAQName & CountPulseCounter, _
                                                  "CountPulses", CICountEdgesActiveEdge.Rising, 0, _
                                                 CICountEdgesCountDirection.Up)
CountPulseTask.CIChannels.All.CountEdgesTerminal = "/" & DAQName & PressurePulseOutputChannel
CountPulseReader = New CounterSingleChannelReader(CountPulseTask.Stream)
CountPulseTask.Start()

Then, every 100ms (via .NET timer control), I obtain the count as follows:

    Public Function GetCount(ByRef ErrMsg As String) As Long
        Dim tmpCount As Long
        Try
            tmpCount = CountPulseReader.ReadSingleSampleInt32()
        Catch ex As Exception
            'CountPulseTask.Dispose()
            ErrMsg = ex.Message
            GetCount = ErrLong
            Exit Function
        End Try
        GetCount = tmpCount
    End Function

I've got an intermittent but reliable situation where the GetCount sub throws an exception--sometimes after 8k counts, sometimes after millions of counts.  I haven't seen this issue on my dev system, but my client has seen the error on their deployment system.  As a result, debug information is limited--I know that makes diagnosis very difficult.

But i'm wondering if anyone is aware of any reasons why a ReadSingleSampleInt32 call would work fine for millions of cycles, and then all of a sudden throw an exception. Not knowing the specific error, it's been hard to search the forums for possibilities.  I can confirm with near certainty that the counter task is still valid and running.

Any thoughts would be greatly appreciated.

Thanks!

Sandheep