SD Mounts Drive but how do I unmount it when done?

[drpiety]

Hi,

It is really nice that SD mounts my Lacie Drive to make the Backup. What I cannot manage without error message is to unmount it. After Completion I run the script:

 do shell script "diskutil unmount /Volumes/Lacie" user name "USER" password "PASS" with administrator privileges

The drive is unmounted but I get a failure message in the log.

Please help me to get rid of the ugly red line in the log and keep in mind that I have no knowledge of scripting. I found those lines on the net and they make sense but SD does not like them.

Thanks