My setup: 2011 MBP 13" i7 16GB RAM, 480GB SSD TB connected to LaCie 2Big Disk with 4TB storage Daisy chained to Dual Link display adaptor, which feeds into a Samsung SyncMaster XL20 (resolution 1600x1200). Normally I would use the MBP with the lid closed, an external KBD and mouse. I boot the MBP with the lid open, then close the lid. The MBP is powered via the mains charger. The problem: If the MBP TB cable plugs into the UPPER TB connector on the LaCie, and the Dual Link DVI into the lower TB connector on the LaCie, the screen is unusable. If I reverse the cables on the LaCie, then the screen works, but with regular horizontal "flicks" every few seconds. If I take the LaCie out of the equation, and plug the Dual Link DVI adaptor into the MBP, then the display is rock solid and beautiful. Questions: I thought that the TB connectors should be "symmetric" and not dependant in IN/OUT. Am I right or wrong? Anyone tried a similar arrangement and can comment? Is my LaCie likely to be faulty? Note, disk access is perfect.