If by CLI, you mean the linux console then, it's probably that you're using a vesa framebuffer console and the mode(resolution) its set to doesn't match the native resolution of your laptop screen. Some laptops will try and scale the display, often resulting in fuzzy image quality, others will just center and put a border around the image.
The VGA= kernel option is probably what you need to look at. My guess is it'll be specified in the grub config somewhere, but it's been a while since I've looked at debian (or grub for that matter), so rather than give you duff information, I'll leave you to investigate further.
Last edited by GazL; 04-08-2009 at 05:43 AM.