I am trying to get 24bpp on the Toshiba 8000 laptop. When using 24bpp, X starts, and gnome appears correctly. The menu icons on WP8.0 and netscape are black/white and all messed up. I can display a full-color GIF and gnome appears correctly. For now, I am using 16 bpp mode.
What version of X are you running. You will want to upgrade to the latest packages that are available on the updates site (XFree86-3.3.3.1-49) Reopen this bug if this release does not solve your problems.