9 gig HD w/os 3.9

[CaptainHIT]

HD's over the 4GB limit are supported with OS3.5 and up.
In your case i would check if you have the NSDPatch.cfg file in the SYS:Devs drawer.

Normally it's copied to there when you install OS3.5 or OS3.9. If you cannot fix it that way, try to install IDEfix97 from aminet. It needs a key, but at least you can see if your HDD will be recognized as a 9GB one.

[CaptainHIT]

Now i remembered something too, maybe the cylinders and heads aren't set to the right values.

Compare them to what says on the HDD and what it says in HDToolbox. If they're different, you still can adjust them in HDToolbox, just select your HDD from HDToolbox' menu and click on Install. There you will see the parameters and other values you can correct if it's needed.

I cannot think of any other stuff atm what could help...