Visual Basic

Public Sub Modem_DataArrival(ByVal sender As Object, ByVal e As DataArrivalEventArgs)
        ModemTests(0).ModemInfo += e.RecievedData 'there is data in here when it crashes

        If e.IsComplete Then
            If ShowingModem = sender.tag Then
                ModemTests(0).ModemRunning = False
                Dim d As New SetTextCallback(AddressOf ShowModem)
                Invoke(d, New Object() {ModemTests(0).ModemInfo}) 'error occurs here
            End If
        End If
    End Sub

System.ArgumentOutOfRangeException was unhandled
  Message="Length cannot be less than zero. Parameter name: length"
  ParamName="length"
  Source="System.Windows.Forms"
  StackTrace:
       at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous)
       at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args)
       at ConnectionTools.frmMain.Modem_DataArrival(Object sender, DataArrivalEventArgs e) in D:\VS2008\WindowsApplication10\WindowsApplication10\frmMain.vb:line 72
       at ConnectionTools.HttpRequestResponse.OnDataArrival(DataArrivalEventArgs e) in D:\VS2008\WindowsApplication10\WindowsApplication10\clsHttpRequest.vb:line 51
       at ConnectionTools.HttpRequestResponse.ReadCallBack(IAsyncResult asyncResult) in D:\VS2008\WindowsApplication10\WindowsApplication10\clsHttpRequest.vb:line 199
       at System.Net.LazyAsyncResult..ctor(Object myObject, Object myState, AsyncCallback myCallBack, Object result)
       at System.Net.ConnectStream.BeginReadWithoutValidation(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state)
       at System.Net.ConnectStream.BeginRead(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state)
       at ConnectionTools.HttpRequestResponse.ReadCallBack(IAsyncResult asyncResult) in D:\VS2008\WindowsApplication10\WindowsApplication10\clsHttpRequest.vb:line 191
       at System.Net.LazyAsyncResult.Complete(IntPtr userToken)
       at System.Net.ContextAwareResult.CompleteCallback(Object state)
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Net.ContextAwareResult.Complete(IntPtr userToken)
       at System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
       at System.Net.Sockets.BaseOverlappedAsyncResult.CompletionPortCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped)
       at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)
  InnerException: