C.D. recognition problem

Hi,

Lately I am facing the folling problem with my cd drive.
I have a LG DVD Writer in my PC.
Suddenly my cd drive stopped recognising c.ds.
The light on the c.d. drive is glowing stating that the c.d is being read but the c.d. is not recognised. I have tryed this by different c.ds but in vain.

But suprisingly if i insert a DVD, its getting recognised.

Please help me out ASAP.

Thanks,
Bhaskar.