Great Plugin. Just what I need. But I am using Suffusion theme with ajax to change page content driven by video. Ajax page changes cause left and right sidebars to scroll on ajax content change first to position -490, then to -260 (I think it was -260 . . .) so they were nearly hidden at top of page. Scroll bar manipulation then brought them to where they should be, but problem made plugin unusable.
My fix (works for my situation anyway) was:
Math.max(--your strx-magic-floating-sidebar-maker.js line 78 here--,0);
That seems to do the job,locking sidebars and content together, but I don't know why without further examining your code!
Currently working in localhost, no site view available.