gprs shield serial comm

ive got the GPRS shield v2.1
is there a way to communicate with the shield using a dumb terminal? (without an arduino or other microcontroller)
ive tried using pins D0 & D1, with the board jumper set to hardware serial, with my terminal set to 19200 8N1 with no success.
ive also tried using ping 7 & 8, jumper set to software serial, again without success.
im using a plain old 9pin rs232 cable, using pins 2 & 3 (RXD & TXD)

has anyone else tried to make this work?

You can not connect RS-232 output and input to gprs board.
The voltage level for serial input/output in gprs board is 5 volt while rs-232 is -12 to +12volt