Keys missing if typed quickly in firefox after the browser is in use for a while

Binary package hint: firefox

After firefox is up and running for a while, when I type too quickly it seems to miss every other key. For instance, if I type www.ubuntu.org in the address box, sometimes it only captures 'wwuut.r'.
It happens consistantly when couple of tabs (yahoo and google mail box) are open.
If I close the browser and re-open it, it seems to accept all keys strokes (www.ubuntu.org) and the problem comes back after few minutes.
I noticed that the issue is only with firefox browser. If I open a gedit, the app accepts all keys I enter.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: firefox 3.6.12+build1+nobinonly-0ubuntu0.10.10.1
ProcVersionSignature: Ubuntu 2.6.35-23.41-generic 2.6.35.7
Uname: Linux 2.6.35-23-generic i686
Architecture: i386
Date: Wed Dec 8 20:22:19 2010
FirefoxPackages:
 firefox 3.6.12+build1+nobinonly-0ubuntu0.10.10.1
 firefox-gnome-support 3.6.12+build1+nobinonly-0ubuntu0.10.10.1
 firefox-branding 3.6.12+build1+nobinonly-0ubuntu0.10.10.1
 abroswer N/A
 abrowser-branding N/A
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: firefox