Sonnet engineering has fixed this issue with some Fusion storage systems. This issue was addressed and fixed as follows:
APRIL, 2008: in Fusion D400Q and Fusion D500P systems with serial numbers beginning with J.
MAY 20, 2008: In Fusion D800RAID with serial numbers beginning with G.
All versions of Fusion R400Q and R800RAID are compatible with Seagate ES.2 Drives.
Note: Seagate ES.2 drives have lower performance than Sonnet recommended drives.
The bus lanes actually get set correctly under Mac OS X 10.5.6 but they are not reported correctly in the Expansion Slot Utility. The actual settings can be verified by booting under another version of Mac OS X. Sonnet has filed a bug report with Apple.