Apps :: No HD's in Mount Tool

Hi,

I can't mount any HD's using the mount tool most of the time. Yesterday I suddenly saw them appear once in the mount tool and in fstab, but that was the only time and now they're not visible in fstab and the mount tool any more.

What can I do to add the HD's to the mount tool when they're not visible?

TIA, Diogenes

original here.