I got my first apple at the beginning of September and have been really happy with it for the most part. A couple months ago it started behaving strangely, I noticed that when I tried to burn a CD in iTunes that it said Preparing Disc and took almost a half hour to prepare before it would write the disc. Then I noticed that it would lag up momentarily and just overall perform slow(skipping in music, delays, momentary freezing). This is very frusterating for me, I've run a diagnostic check on all my hardware and nothing comes up. Can anyone help?