Firefox can be tracked by evercookie even if configured to delete all contents when quit and dom storage disabled

Binary package hint: firefox

i found that firefox can be identified by websites through several technologies even with heigh privacy settings.

http://samy.pl/evercookie/ reports the same number after ending a session and quitting firefox.
this should not happen because the preferences are set to delete history, cookies, download-history, active logins, search terms, cache, saved passwords and offline website data when quitting.
also dom.storage.enabled is set to false in about:config.

here is the output of the evercookie script:

userData mechanism: undefined
cookieData mechanism: 283
localData mechanism: undefined
globalData mechanism: undefined
sessionData mechanism: undefined
windowData mechanism: 283
historyData mechanism: undefined
pngData mechanism: 283
etagData mechanism:
cacheData mechanism: 283
lsoData mechanism: 283
slData mechanism: undefined

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: firefox 3.6.10+build1+nobinonly-0ubuntu0.10.04.1
ProcVersionSignature: Ubuntu 2.6.32-25.45-generic 2.6.32.21+drm33.7
Uname: Linux 2.6.32-25-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Wed Oct 20 01:50:17 2010
FirefoxPackages:
 firefox 3.6.10+build1+nobinonly-0ubuntu0.10.04.1
 firefox-gnome-support 3.6.10+build1+nobinonly-0ubuntu0.10.04.1
 firefox-branding 3.6.10+build1+nobinonly-0ubuntu0.10.04.1
 abroswer N/A
 abrowser-branding N/A
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100223.2)
ProcEnviron:
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox