I am having problems with gnome3/X on an old Sony Vaio. Its had gentoo/gnome2 on it for years but after this upgrade to gnome3 gdm stops at a black screen with a rotating cursor.
So far I have tried 3.1.1 and 3.4.4 kernels plus rebuilding everything I can think of. KMS looks like its set correctly (intel i915) The basic X server can run using twm. Any hints where to look next as the gdm logs arent very informative. BillK