Gnome ignores scrollbar drag on rightmost pixels

[Cefn]

In previous window managers and themes I've found it convenient to move my mouse across to the extreme right of the screen, where I can then scroll the window, typically without moving my eyes from the text I'm reading or the other work I'm doing.

In Ubuntu Gnome this is impossible, because the default theme and window manager behaviour ignores mouse drags at the extreme right of the screen, creating a serious usability issue for almost every program I use on the desktop, including the browser I'm using to author this bug report right now!

Instead of requiring my mouse to be within the horizontal X coordinate of...
SCREENWIDTH - SCROLLBARWIDTH -> SCREENWIDTH [easy to achieve by just throwing my mouse to the right]
...Ubuntu gnome requires my mouse X coordinate to be within something like...
SCREENWIDTH - (SCROLLBARWIDTH -2) -> (SCREENWIDTH - 2) [very hard to achieve and needs visual check and fine mouse control to position the mouse within an incredibly narrow column]

Preferably, this would be fixed by intelligent event capturing and routing those events to the scrollbar, even though the fancy look and feel would strictly leave unresponsive pixels to the right of the scrollbar.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: gnome-themes-standard 3.8.1-2ubuntu1
ProcVersionSignature: Ubuntu 3.10.0-6.17-generic 3.10.3
Uname: Linux 3.10.0-6-generic i686
ApportVersion: 2.11-0ubuntu1
Architecture: i386
Date: Wed Jul 31 16:36:23 2013
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-themes-standard
UpgradeStatus: No upgrade log present (probably fresh install)