SIM900 GSM shield: How to switch between software and hardware UART

Development Tools IDE 1.x
3

Thank you for your answer.

First I tried, to switch to the MEGA library to use Hardware Serial. I have done this:

  1. In the GSM.h decomment Arduino Mega
    //#define UNO
    #define MEGA

  2. In HWSerial.h decomment Arduino Mega
    #define MEGA

But it can not compile:
SIM900.cpp:143: error: '_tf' was not declared in this scope

The problem is, that "_tf" is only created in GSM.h if it is a UNO:
public:
#ifdef UNO
WideTextFinder _tf;
#endif

I have just seen, that the error is posted here:
http://code.google.com/p/gsm-shield-arduino/issues/detail?id=47

Can anybody help me, how I can fix it, to use HardwareSerial with my GBoard?