http://youtu.be/Q4jbkXiGPbs
I don't have a video of mine at the moment, but here's a random link to a video of a top operating properly.
It's hard to tell on your video, but it looks like the material is getting bunched up on the drivers side...? The motor does sound like its struggling, and the lid gets hung up a bit as it's flipping up. Could just be how the mic on the camera is picking up the sound though.
Quick question: have you had the tracks cleaned and lubed?