It is hard to believe that there are 40k glitches removed. Anyway, Nero CD-DVD Speed treats some upsurges of PIE/PIF as glitches and do not show them in the graph. However, some of those automatically removed "glitches" are indicative of errors inherent to the disc and should not have been treated as such. You'd better use KProbe to have control over removing high spikes as glitches or not.
BTW, it is not certain whether the PI/PO error rates reported by Liteon 165P6S are predicative of the errors to be encountered when the files are read by the same unit.