no context menus on right click

Binary package hint: firefox-3.5

For a period of time, no context menus would appear when I right-clicked anywhere on any page in Firefox. Right clicking worked elsewhere in Ubuntu. I restarted Firefox, and the problem persisted. I restarted the system and the problem persisted. Suddenly, the problem corrected itself.

ProblemType: Bug
Architecture: i386
Date: Fri Jan 15 13:29:26 2010
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
Package: firefox-3.5 3.5.7+nobinonly-0ubuntu0.9.10.1
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-16.53-generic
SourcePackage: firefox-3.5
Uname: Linux 2.6.31-16-generic i686