I'm using gedit 2.30.3 . Even when the window is maximized, if I put the cursor all the way to the right to the scrollbar area and click to move up or down a screenfull of text, it won't do it! It's like gedit allocates a pixel at the extreme right just to annoy me! I have to carefully position the cursor in the scroll area. What is going on and how can I change this behavior?
There is a documented bug about this.
Three methods of dealing with it that I know of:
Live without scrolling by page the way you would like to or are used to.
Workaround by using a different method of scrolling full pages (e.g. PgUp/PgDn keys, assigning some modifier key to make scrollwheel scrolling go by page, etc.)
Following some of the links and linked bugs in that page I found someone suggested using the xrandr program to fool the computer into stopping his mouse just short of the edge. This was mentioned in comment 10 of bug 206837.