That's strange, since A1 one only differs from A2 with regard to the LEDS used....
That's what I thought too, expect if you look very carefully at the bottom of the US DIR-655 product page, in tiny tiny little letters it says:
"SharePort upgrade is available for the hardware versions A2, A3, A4."
So presumably, A1 can not do Shareport. More than just the LED's....
Also, apparently A1 and A2 are not "Green" devices as it also says:
"D-Link Green references contained herein apply to Hardware version A3 or later."
jB