HY-SRF05 sensor to arduino

i am a total newbie to arduino. i was connecting my HY-SRF05 sensor to arduino when i ran into a strange problem.... when i connect my the vcc to 5v and the ground to ground from arduino .. it powers off (lights go out) .. i initially though that maybe i hard wired something wrong but when i crossed check the circuit everything was fine

any ideas as to why this happens and how to fix it

thanks