I have an OSX.2.8 Ibook with a version 3.2 DVD player. Up until today, I've been able to play dvds with no problems, but today, when I tried to put dvds in, the computer wouldn't recognize them, the dvd player spun and made a clicking sound a few times and then ejected the dvd. I tried several different dvds to no avail, although the computer did recognize game discs. I went into the CD and DVD system preferences, but didn't notice anything unusual, and I haven't installed anything new recently. What should I do to fix this problem?