the main problem is the media, on which you are burning it too. if the media is of good quality, then burning at higher speeds is actually recommended. but some companies (e/g memorex) have importers shipping imitation media to retailers. you wouldnt know the difference unless you buy a pack, and check the serial #. I read a huge article on counterfeit media, and how it gets to stores. reportidly, there are types from different regions that are just chap-o knock offs of the name they carry. If i come across that article again, i'll have to post it. it's really a mind blowing read.