thats not enough info to determine the reason, got some questions
what program did you use to burn it and is it the latest version?
was the antivirus resident protection disabled when you burned it?
whats the mediacode of those medias? use dvdidentifier and report results
click here ,
did you do other stuff while burning? for example surfin sites/playing mp3s
check dma settings see this guide also check dma settings in bios make sure its set to auto
if you used nero to burn it open C:\Program Files\Ahead\Nero\NeroHistory.log copy & paste the latest but without neros serial , if you used other program then i suggest youll use nero as not all programs save logs+imo the one nero saves provides alot more info then others , also run nero infotool click the floppy icon which is after the drive name click "save" and again "save" open the saved file copy & paste