dvd burning problem

I can't figure this out. about a week ago every dvd burn I've made has been unsuccessful. One thing i noticed that was kind of weird that hasn't happened to me in a long time is when i open programs that need to pull memory the buffer starts to fluctuate, and sometimes if the program takes too long to open if can hold up the entire write process by saying "waiting for hard drive to recover" or something of the sort. On top of that even though the burns are successful, they never read. I've switched out dvd drives and i'm still having the same problem. I thought it might be the media, but my brother burned something on his laptop and it worked fine... what could it be?