Firewire HD case with Prolific PL3507 bootable?

I recently purchased a Firewire/USB2 Combo HD case (HD-D2-U2FW ). This case equips with two Firewire ports so that I can use one to connect my iBook and another for slim DVR-K11 Writer.

Actually I have another Firewire HD case (
HD-337 Combo) installed with a 5 years old Maxtor 6.4GB. I had already installed Panther on this external drive. With Jaguar in the iBook's internal harddisk, I can dual-booting it sucessfully (by setting Startup Disk or pressing Option button when start). However, after swapping the external disk to the new case, it was unable to boot. Swapping back to HD-337 case everything is normal. I originally thought that I have a faulty case, but the disk in the new case is able to mount on Jaguar and I am able to see its content. It is just that my old iBook 2001 cannot detect it and boot from this device.

I started Apple System Profiler and check the Firewire device. The manufacture name is "Prolific PL3507 Combo Device". Anybody who has this device and is bootable, or has the same experience before, please let me know.