[dnanian]

OK. Internal partitions must not allow for simple ejection like this. What you'll have to do instead is crib from my script, and do something like:

		tell application "Finder"
			try
				set diskID to my getDiskIDByName("the-volume-name")
				
				if diskID is not equal to "" then
					do shell script "diskutil unmount " & diskID as string
				end if
			end try
		end tell

In your own script, copy my definition of "getDiskIDByName" and paste it in.

I don't know why it doesn't know about your SATA drive -- that's just weird...