I've got a problem with a Lacie esata drive not being recognized when connected to the esata port on a Lenovo Mini dock plus series 3 port replicator. It looks like the esata port isn't supplying any power to the drive. The drive does work when plugged directly into the esata port port on a T410s.
As a test I connected the drive using esata on the base and a usb-> power adapter that came with the drive and it did work. Which likely indicates that the port rep is either supplying not supplying power to the esata port.
The T410s uses an eSATAp socket that carries power along with acting as a USB port. while the LaCie drive probably included an eSATAp cable with it. If you tried a standard eSATA cable with it, it wouldn't be powered.
If you want to use a single cable, you'll have to use the onboard eSATAp port on the T410s because the T400s came out after the T400/T500/W500 and their respective docks. so, the dock had eSATA before the T400s had eSATAp. since the same dock is being offered with the new series, the docks don't support all capabilties of the newer systems
eSATA is in a transition stage right now. soon we'll see eSATAp take its place in the market and become more ubiquitous.