Yes it's voodoo, but we are the witch doctors! :bigsmile:
I think it's likely, although I'm not sure, that the BenQ DW16xx drives report only E32 errors as C2. E32 is the worst kind of C2 errors, and it means that C2 error correction has failed (except for some drives that can correct E32 in some cases).
C2 errors consist of E12, E22 and E32.
Drives that can scan for C2 errors report this differently, but any accurate scan should include E22.
AFAIK the E12 errors are usually not included when reporting C2.
Plextor drives report C1/C2 this way:
C1 = E11 + E21 + E31
(E12 ignored)
C2 = E22
CU = E32
My guess is that the BenQ reports it this way, but I'm not sure:
C1 = E11 + E21 + E31
(E12 and E22 ignored)
C2 = E32