after getting bad result for second, third and fourth burn, i decided to upgrade firmware to AL15.
i'm also clean the learned media after upgrade firmware.
i started to burn again. the PIE/PIF spike at layer break reduced. so i burn again, as predicted, the PIE/PIF spike reduced.
at the third burn, there is still a spike, but PIE not reach 100 point, and the PIF not reach 4 point.
at the fourth burn, everything back to normal.
yupz, maybe is bad batch.
pheww.... i'm so relieved.