lcd-screen flickers on acer 1310

i'm am newbie on unix/linux systems, but
i really wanna get off the Windows-train.

i installed knoppix 3.3 on hd on my acer 1310 laptop.
i managed to connect to the net, but my screen is flickering.

i've gone already through some posts and i already
tried many things:

cheatcodes like
screen=1024x76
video=vga16:off

but nothing has changed. also using kxconfig brought nothing new, after rebooting the initial values were the same! (640x400, 75mhz instead of 1024x768 and 60)

i read can achieve my goal through manipulating /etc/X11/XF68config but i'm not sure where exactly to change the values, and also which values are
appropriate. i know that 60mhz should work fine, but in
the XF68config file were HorizSync and VertRefresh values...

can anybody help me? the screen causes headaches! :x