Securom protection

[Bill_st]

I'm trying to copy a copy itself of Diablo 2: Lord of Destruction, that reads fine in any cd-rom (1:1 copy) using Clonecd, I'm using an LG GCE 8160b 16x, and check both Read Subchannel data from data and audio tracks. The resulting copy reads fine in my CD-ROM drive (LG 52x), but will not pass the game protection in my DVD-ROM drive (pioneer 6x), and the dreaded "insert the original CD" message pops up. Nonetheless it reads fine the directory structure, it is not a readibility problem with the media (verbatim 16x certified). The funny thing is, the source copy plays fine in both drives, what could be the problem?