Strange power problem

I am making a line follower with arduino

so here is my setup

moter driver have 8 pins for
5 motors
2 pwm
vcc
gnd

driver http://robokits.co.in/shop/index.php?main_page=product_info&cPath=1&products_id=176
now some strange stuff

when i attach grd then every thing is okey but when i attach vcc it takes power which is provided for motor to arduino. i dont know arduino runs or lit up led only

second thing is when i pwm pins it light up sensors and ALL led ( exept pin 13) pwr tx and rx and sensors which are taking power from 5v and gnd on arduino

when i attach pwm nothing works

please help

please anybody help me

when i attach grd then every thing is okey but when i attach vcc it takes power which is provided for motor to arduino

What is "grd"?
Could you maybe rephrase your question, post a sketch, show a schematic?

As above although it does sound like you're trying to run 5 motors from the arduino?

now its okey. when i power motor driver it lit up arduino led but not arduino

But main problem is i can power teds for sensor they are dim when powered with 9 v no problem in usb

Its problem when there are more than 2 sensors

is there problem arduino for providing power

is it possible to provide power to arduino throgh it 5v pin because when i connect vcc pin to arduino then arduino start up. And circuit can i run without connecting both ground

Main thing is please suggest that do i need to provide seprate power to sensors

No sorry, it isn't making any sense.
You don't say what the sensors are, though unless they're taking an awful lot of current, it seems unlikely they're causing problems.

A schematic would be a great help.

Have you got grounds connected?
Have you double and triple checked your wiring?
Could this be a decoupling problem?