i got a new 16x burner at work a couple months ago
put it into a win98 pc and it made coasters at 16x all the time, even at 8x it would make coasters half the time
put winXP onto it , upgraded the nero burning rom to the latest for XP and now its SOLID! no coasters, although it usually only burns at 12x, but i think thats due to the cpu speed (software calculating 12x as the max for the system config, i think)