The over-head pinch problem is one of the oldest known and was solved by a practical mod in thread "overhead pinch trap" http://www.robotreviews.com/chat/viewtopic.php?f=20&t=15853&hilit=overhead+pinch+trap
There are specific technical requirements to any bumper addition, from the response programmed to bumper sensing, dependent on fine details of maneuvering and the robot geometry.
(links to threads on various problems with furniture are in the Mods & Repairs list main forum page).
Sometimes it is more attractive to raise a piece of furniture slightly, sometimes more to fix the robot -- a matter of taste and circumstance. Mag strips have even been used to block off problem furniture, but fixing the robot can be attractive. Other problems require lowering the bottom edge of the bumper, also quite practical.
Some other brands, with camera guidance, detect such blockages with more elaborate IR sensors.
For Neato I think the Vorwerk VR200 Neato model even adds bumper sensing to the laser turret itself. That feature was never added to the Neato Robotics models. (Vorwerk is not distributed outside Europe.)