I had the same problem with a Acer laptop i sent back a while ago, i was complaining about the temperature of my fan back then. 1 Month later Acer brung my laptop back to my house, working well. Until i was wanting to burn some music and data files onto one DVD (4.7GB) and it wouldn't read it. Although try pushing the cd/dvd drive in, and keep your finger on it and see if anything pops up then.
All the best
Jake