I have purchased my MacBookPro in October 2007, after 6 months my optical drive was so picky in reading or writing DVDs and CDs, and after few months, it was able to read originals only.
I tried everything from updating the firmware or flashing it to restore its original firmware, but no luck, until yesterday when i had to format and install the OS from scratch, but to my surprise it wasn’t able to read the Original MacOS DVD.
I Googled once again about the cuase of this, and found some results referring to cleaning the lens,
I followed this tutorial to disassmble the laptop :
and this one to disassmble the optical drive and clean the lens with benzene,
In 1 hour i had my superdrive working as brand new one and saved me from buying a new one 
, i know many who face the same problem with the optical drive, this was a nice way to have it back.