Originally Posted by daemonfowl
how to set X the correct way ? two lines one vertical left and the other horizontal low cross the already small screen ..
by the way , when I installed openbsd 4.8 on this very ibook , this didn't happen and X nicely fills the screen ..
This last sentence is the most salient. Since none of us are there to look over your shoulder, we can only go by the information presented thus far which isn't very tangible.
The first place you should look is /var/log/Xorg.0.log
which is where Xorg tracks what it thinks is going on. Posting its contents here may help us direct you forward.