I'm have problem with writting with my 812s. It seems that whenever I try to burn anything there are these spikes in PI/PO. Usually for most of the disc the PI/PO is pretty low like around 20. And then once in awhile it'll spike up to 200-600. Don't know what's doing it. I usally don't do anything on my computer when I'm burning. I turn off all programs including anti-virus. I've tried Nero and CloneDVD2 and get similar results. Here's one that I just burned.
Burned w/ Nero 184.108.40.206, 812s @ 4x w/ US0J w/ speedhack and auto-bitsetting.