Thanks for your answer.

Yes, the cheatcodes helped me. I found for my notebook Amilo La1703 the best combination is: knoppix nodrm nofb no3d|nocomposite.
But I don't think I'll use V6.7.1, because I found these problems (in the first half hour):
1. When setting my DSL connection, after pressing the Save button, Network Manager crashed. Well, I could it restart with Root Terminal (root@Microknoppix:/home/knoppix# NetworkManager) and then the connection worked, but at V6.4.4 there is not such problem.
2. VLC once opened couldn't be closed, only killing it with System Monitor.
However I found a positive thing: Gnome Player workes with full screen at V6.7.1 (at V6.4.4 my system restarts if I swith the full screen with mplayer).

I downloaded LibO_3.3.0_Linux_x86_helppack-deb_hu.tar.gz and LibO_3.3.0_Linux_x86_langpack-deb_hu.tar.gz (V6.4.4 has LibreOffice 3.3.0). But I couldn't install the debs with dpkg: there was unsatisfied dependences (libobasis... ... ...).

For all who wrote to me:

Actually I succeded to install somehow LO with Hungarian language, but I am not very satisfied with this installation...
I removed with Synaptic libreoffice-core and the packeges that needed selected for this. But at the end I got: 'An error occured! E: postgresql-common: installed post-installation script alfolyamat 1 hibakóddal kilépett (... subprocess exited with error code 1)'.
But the LibreOffice package was removed.
After this I downloaded the newest LO from it's website (LibO_3.4.4_Linux_x86_install-deb_en-US.tar.gz, LibO_3.4.4_Linux_x86_langpack-deb_hu.tar.gz, LibO_3.4.4_Linux_x86_helppack-deb_hu.tar.gz) and I succeded to install it with dpkg.
This LO version seems to work perfect, the only thing what flusters me is that error message.