FireFox down arrow for scrolling a web page does not appear

[Dino brown]

Binary package hint: firefox

Unless Firefox is expanded to full screen size, the bottom scroll down arrow in the scroll bar appears as a small dash and cannot be 'clicked' by the mouse. When the mouse scrolls over this area, it converts to the 'change window size' mouse icon and can be used for that function only.

release: Ubuntu 11.04
version: firefox: 4.0.1+build+nobinonly-0ubuntu0.11.04.1
Gnome: gnome classic no effects

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: firefox 4.0.1+build1+nobinonly-0ubuntu0.11.04.1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
Architecture: i386
Date: Sat Apr 30 11:23:10 2011
ExecutablePath: /usr/lib/firefox-4.0.1/firefox-bin
FirefoxPackages:
 firefox 4.0.1+build1+nobinonly-0ubuntu0.11.04.1
 flashplugin-installer 10.2.159.1ubuntu1
 adobe-flashplugin N/A
 icedtea-plugin 1.1~20110420-0ubuntu1
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox
UpgradeStatus: Upgraded to natty on 2011-04-29 (0 days ago)