I have received the same result. I have spent quite a while patching the source code to be more flexible (ie. to allow the user to choose different UARTs, but all of them seem to be already locked by some system application (error code -14 means KErrInUse - see include/e32std.h). So I suppose that there is some mechanism of sharing the comm port. Does anyone know about it or did anyone make a serial port application to work ?