My Quicktime player isn't working

Hi,

So I got a new Netbook for Christmas and I downloaded iTunes and Quicktime Player. I tried to load a DVD on an external disc player and it won't read it. It reads CDs fine so I don't know what the issue can be. I went to the help site for Quicktime and it said to drag the DVD information to the Quicktime Player icon and I did but it comes up with:

Error -2000: a necessary data reference could not be resolved (/)

Can anyone tell me what this means and what I can do to fix it.

Oh, and if it helps I have an Acer Aspire One Happy Netbook 🙂

Thanks,

BlackButler