So basically, since i done a fresh vista install i've been getting many errors when i try and burn anyting at 8x, i know its not the discs(or maybe it is?) because when i burn at 4x i have no problems. The drive in question is an LG-GSA-H12N. I've unistalled the drive a few times now and that hasn't fixed the problem, i'm also up to date on the firmware side of things. I've also tried a few different programs, Ashampoo(aswell as ImgBurn) for instance will just fail completely if i set the write speed to 8x making the dvd useless, whereas express burn will just burn at 4x when i set it to 8x, so i've saved myself a few coasters using Express Burn at least.
The rule of thumb around many sites, is that the burning speed should be no more than half the maximum listed on the package. Burning at 4x on 'Verbatim' or 'Taiyo Yuden' (assuming everything else is up to date) seems to work best.
What are you looking for then? What is the brand or MID of the discs you're using? What's the printed speed of said discs?