Wonderfull behavior of 6600 in outgoing call listener

Hi,
I just want to detect an outgoing call disconnect it then make a new call,
but when the run reaches to Dial method the iStatus of my RunL encounter with an error, -9 (KErrOverFlow),

what does it mean,
I am running the code on Nokia 6600,

The RunL code:

+++++++++++++++++

if (iStatus == KErrNone)
{
if (iCallStatus == RCall::EStatusHangingUp || iCallStatus == RCall::EStatusIdle || iCallStatus == RCall::EStatusUnknown)
{
iCall.Close();
if(iFlag )
{
TBuf <100> newCallName;
iCall.OpenNewCall(iLine, newCallName);
iCall.Dial(_L("03656655"😉);
}
}
else if(iCallStatus == RCall::EStatusDialling)
{
if(iFlag )
{
iFlag = false;
}
else
{
iFlag = true;
RLine::TLineInfo lineInfo;
iLine.GetInfo(lineInfo);
iCall.OpenExistingCall(iLine, lineInfo.iNameOfLastCallAdded);
iCall.HangUp();
}
}

iLine.NotifyStatusChange(iStatus, iCallStatus);
SetActive();
}
else
{
WriteToFile(iStatus.Int());
}

+++++++++++++

Is there any Idea? this code works correctly on nokia3650 and SEP900,...
If the red line be in comment, the code works correctly, but when it calls here the -9 occured in iStatus,,,
and also the Dial method itself returns 0 which means KErrNone... !!!

(the version of this 6600 is: V 5.27.0)

Thanks