I have a 40GB western digital and i did had to run any special tools to make the system recognize it as a 40GB HD.
What version of scsi.device are you using? I hope not the OS3.1 one. I'm using the IDEFix package from Aminet. Try it.
By HDInstaller you mean HDToolBox? Try HDInstTools. Perhaps it's better.
Edit: Right.. I forgot to say that i had to set the size of each partition by increasing the cylinders value, not by using the size slider as it was reseting to 0 beyond the 8GB.
