Hi, had simialer prob when installing onto my desktop system connected to a LCD panel. What I had to do was to reinstall from scratch and instead of doing the X11 config thing auto or manual I selected the third option (if I remember correctly) which was something like go let the config program try and figure it out!! This got the display working but I then had a desktop of 1600 x something weird like 2400 so I could scroll down and down and Down !! Anyhow, I was then able to modify the settings/display settings where I found the correct resolution 1600x1200 and everything is working fine. Obviously your optimum resolution wil be different but hopefully it will be displayed and selectable in the display settings. Also xorg.conf file was setup with the correct lcd name, horiz/vert refresh rates etc etc.
I did try editing the xorg.conf file before doing this but it had the correct freqs already, but it did not state the lcd panel make and type. The screen still did not work so I tried the reinstall above.
Hope this might help!