Well... I think your "grey bars" are scrolling bars?
This feature appears (on my computer) only, when you use 2 fingers (with scrolling move - horizontally or vertically) on the pad and allows you to scroll without mouse or arrows keys - just let you left finger stay on pad and move your right finger (vertically or horizontally). Not every program dispaly this bar: Word - yes, WordPad - no.
When you get up your fingers from the pad - this bar disappears.
It works OK, but I don't use it in my everyday with NB550D.
I don't know why it's not working OK on your Toshiba. But maybe let try combinaion Fn+F12 to see what happen
