My dvd drive doesn't work on the same rail as my graphic card but will

How did you plug in the DVD player into the same rail? Unless you spliced the wires...

Just 2 questions here.

1. What video card do you have?
2. What power supply do you have (specs/wattage, and brand)?

Most probably that rail does not have sufficient power to power both VGA and DVD drive.
But to be sure as IH8U asked please state the exact components you are using like PSU / VGA / DVD.

I'm using an Indian Brand PSU, don't remember which exactly. Lite-on DVD Writer with lightscribe, and a Zotac 9500 GT 1 GB DDR2. I don't know how they both used the same rails, However I had posted a question about the dvd writer not working with the graphics card and someone suggested that they both are being powered by the same rail. So I just changed the power cord and now my HDD and The DVD are being powered by the same set of wires(came prespliced)

Your not making any sense. You video card is powered by the motherboard, you don't plug it into anything else.

Even I'm confused, all I know is that my PSU is some weird brand that does weird things. With the old cable power cable that I had plugged into the dvd drive, the dvd drive would not work as long as the graphics card was installed. As soon as I removed it the dvd drive worked. Now I realised I had a spare SATA power connector lying around(it's supposedly coming out from the same set of wires that has another sata power cable that's plugged into my hard drive) by plugging this spare cable into my dvd drive, my dvd drive works fine even though my graphics card is installed.

So you had a bad cable. Glad you were able to figure it out.

Whoever told you it has something to do with psu rails, is a complete idiot.

Well higher end graphics cards require extra PCI power... but those plugs would never fit into a DVD drive

If it was a bad cable it shouldn't have worked when I plugged out the graphic card.

And slightly older video cards made use of molex connectors to power the video cards, i expected that was the case.

A 9500GT does not require ANY power connector.

You said you changed the power cable to the dvd drive and it worked.

Sorry I forgot to add "with the old cable" to "My DVD Drive would work with no trouble if I took out the graphic card" in the opening post.

The information about the type of video card was not available to me when i posted it.
Just after my post he mentioned the type of video card he is using  
On a side note there are 9500GT cards that require external power which are delivered with a 6pin to molex converter cables.