Etcquote]But, do you think that this's why I'm getting these weird characters ?!![/quote]
Weird characters is always a protocol issue: protocol being anything from
- voltage levels [liBAUD][/li]
- Etc. [/list]
Arduino cannot handle RS232 signaling levels (voltage). You will get garbage and possibly damage the microcontroller port after a period of over-voltage. RS232 also inverts the signal, so even a resistor voltage divider still requires an inverter.
Continuing to carry on a dialog is not productive. If you have the RS232 version of the GPS then buy the MAX chip or research a alternatives ... If you have the TTL version, any GPS library such ass the Adafruit if Sparkfun libraries should work when configured to 4800 BAUD,
I do not know which GPS you have, you said TTL first and later RS232.