How are your partitions set up? Early versions of the OS3.x FastFileSystem don't really like partitions greater than 2GB.
Are all the jumpers set correctly? The Amiga doesn't support CableSelect well.
As a last resort, you might try IDEFix.
I don't expect these will help, but if you're out of options you might give them a try.
EDIT: Oh, and Welcome to Amiga.org!
