Make sure that the DVD that you’re using is clean. Not always the easiest thing to do when you have kids, but worth it. Oh, my, yes.
Is there any way around this? – I mean, besides yanking the CD-ROM drive and replacing it with a Blu-Ray one, assuming that they make those. I haven’t really looked any of this up yet; when it comes to technical stuff there’s usually a reader out there who can and will explain things.