My Acer Travelmate 291LMi always has troubles with the graphics under Linux (at least when first installing). As I bootet Ubuntu 5.10, the graphical welcome screen within GRUB was not visible. When I continued the installation with ENTER, the screen went black forever.
Then I tried the boot parameter "linux vga=771". With that it works just fine, as with most Linux distributions. Maybe you have the same problem under some notebooks and it helps you.