How do you safely attach the VESA adapter?
Here's the answer: Use a fork. Seriously. Many posts about the difficulty in fully attaching the flange to the VESA adapter b/c there is minimal clearance. So here is the trick: once you attach the flange to the Tb mount with the 8 torx screws, push down (towards the bottom of the display) to rotate the mount a bit further. This will give you a small amount of clearance. Insert a fork into the opening (see attached photo) so it is perpendicular to the VESA mount (and does not impede the rubber striops from touching the Tb display. Now, there shoudl be sufficient clearnace for the two end bolts to mount the adapter to the flange. Continue as described....
MacBook Pro (17-inch Early 2011), Mac OS X (10.7.4), with Thunderbolt display