[600X + Dock III] DMA mode of Second HDD in Dock III?

[moonissimo]

Hi,

I run 600X on Dock III in Windows XP Professional. I installed a second HDD(160GB) at the IDE channel in the Dock III, everything works good
except that the UDMA mode of the second HDD is mode 1.

Primary IDE channel holds the primary HDD (Ultra MDA mode 2) and a CD ROM drive (multi-word mode 2), and Secondary IDE channel holds the secondary HDD but its mode is Ultra DMA mode 1.

Is this natural? I can't get why this second HDD runs in mode 1. Anybody has the same configuration, let me know your configuration. Thanks!