You can see the top of the red filament in the video - it never reaches the second half of the bowden tube nor the extruder. I don't know where pressure would be building up in such a situation since the filament is very free to move within the tube. I was in move material mode both times so those sounds should have been the same (I would think at least!). Additionally, the motor never rotates backward - it just takes smaller steps. Note that even when it was "clicky" the red filament was still moving forward ever-so-slowly and was nowhere near the end of the tube.
Also, I don't know quite how the Ultimaker electronics are set up, but one of my first guesses was the stepper motor driver overheating - My Solidoodle used a NEMA14 for the x axis, so I know what an overheated motor feels like, and the Ultimaker's is definitely not :wacko:. I have heard that people have had issues with the motors skipping steps when the driver is overheating, so I thought that may be the source of the problem. I'd love to switch the drivers on the board if possible (like on RAMPS), but from my initial inspection of the connections on the bottom of the board it looked like they are integrated to the main board.
Oh and psi? pounds? This is part of the same system that has a barleycorn as a unit of measurement - 100% logical basis :-P (I don't care for imperial measurement despite living in 'murica)
Thank you for your help! I'm completely stumped by this issue and am happy to hear ANY ideas!