I had the same problem. As far as I can tell, if you need to use the tools, the software only works under USB.
I have to say that it seems shortsighted to ignore eSATA users, but then I guess that USB is the most popular connection.
It would perhaps have been useful if a readme file disclosed what does or does not work under eSATA.
I believe you will also find that sleep will work under eSATA but wakeup doesn't and has a tendency to lock up WinXP, making the sleep function annoyingly unuseable.
Jan