I had a Pioneer writer in an Acer Travelmate, only a 2x drive though.
Media to stay away from:
Princo (white top) "For Data/Video"
Sony DMR47N2 (2-4x compatible)
EMTEC (former BASF) "For General Use"
Media that worked near perfection:
Ritek G04 4x DVD-R (the ones with the purple top, but also the ones with the white top).
TDK DVD-R (don't know the specs)
B.O.S. DVD-R 4x "For General" (media code seems to be Lead Data): Very cheap discs but they worked flawlessly in my writer.