Try the xorg.conf at http://www.searchtempoblog.com/index.php/ubuntu-804-hardy-heron-on-a-toshiba-portege-2010-how-to-change-the-video-settings/
I have a Toshiba Portege 4000 with a Trident Cyberblade XP and this xorg.conf sorted the 1024x768 issue for me.
Try the xorg.conf at http:// www.searchtempo blog.com/ index.php/ ubuntu- 804-hardy- heron-on- a-toshiba- portege- 2010-how- to-change- the-video- settings/
I have a Toshiba Portege 4000 with a Trident Cyberblade XP and this xorg.conf sorted the 1024x768 issue for me.