gsm.begin(9600) freezes the program

Hey y'all,

I am just taking my 1st steps with an "Aihasd SIM900 850/900/1800/1900 MHz GPRS/GSM/GPS Development Board Wireless Data Module"

I connected 5V GND TX to RX (D0,1) and vice versa and tried a number of code sniplets with the SIM900.h

Apparently they all freeze the second they reach the line

if (gsm.begin(gmsBaud))

Is this a known problem, or am I just dealing with a broken board?

Thanks for your help!