Hello,
FYI, according to Distrowatch, Knoppix 5.1.1 is out, cf changelog and download mirror list:
http://distrowatch.com/?newsid=03956#0
http://spirit.bentel.sk/knoppix/KNOPPIX-CHANGELOG.txt
http://www.knopper.net/knoppix-mirrors/index-en.html
Best Regards,
Gilles

Code:
* V5.1.1-2007-01-04 (see also: Release Notes at http://knopper.net/knoppix/knoppix51-en.html)
- Updated kicker and kdebase (while fixing a nasty bug that made kicker "disappear"
  in all but the first desktop)
- Updated ntfs-3g (writing speed improvements)
- sudo helper for kdesu
- xorg updates from Debian/unstable
- iceweasel/icedove (firefox/thunderbird) updates
- kwlan for WLAN w/ WEP/WPA in Knoppix menu
- added vlan configurator
- fixed "2nd reboot fails" bug when installing Knoppix with reiserfs
  by downgrading grub (http://savannah.gnu.org/bugs/?17957)
- added french translation to mkbootdev (contributed by Jody Noury)
- [CD] removed KDE docs and java demos
- [CD] re-added spanish language support for KDE
- [CD] installed Java-Plugin for iceweasel (firefox)