These errors appear in the Xorg.0.log; sounds like VideoRAM is set incorrectly; Peter's right - you should test with the VideoRAM line removed (just let Xorg figure it out itself).
(II) intel(0): Allocating 5273 scanlines for pixmap cache
(EE) intel(0): Failed to allocate framebuffer. Is your VideoRAM set too low?
(WW) intel(0): Not enough video memory. Disabling DRI.
(II) intel(0): Allocating 5273 scanlines for pixmap cache
(EE) intel(0): Failed to allocate framebuffer. Is your VideoRAM set too low?
(EE) intel(0): Couldn't allocate video memory
These errors appear in the Xorg.0.log; sounds like VideoRAM is set incorrectly; Peter's right - you should test with the VideoRAM line removed (just let Xorg figure it out itself).
(II) intel(0): Allocating 5273 scanlines for pixmap cache
(EE) intel(0): Failed to allocate framebuffer. Is your VideoRAM set too low?
(WW) intel(0): Not enough video memory. Disabling DRI.
(II) intel(0): Allocating 5273 scanlines for pixmap cache
(EE) intel(0): Failed to allocate framebuffer. Is your VideoRAM set too low?
(EE) intel(0): Couldn't allocate video memory