I've had this papercut for a while now, it's time it was fixed.

When I boot up Ubuntu, choosing "Ubuntu...generic" from the grub screen, Ubuntu fails to load. It just sits at the driver/module loading screen. What seems to be the most significant line in this output is "xhost: unable to open display"

If I choose "Ubuntu...(recovery mode)" from grub then it loads OK.

I don't get why this is.

Out of interest I tried enabling boot error logging with

#/etc/default/bootlogd
BOOTLOGD_ENABLE=Yes

but I'm not seeing anything in that file.

ETA:

I've had this problem since fresh install of 11.10.

Here's lshw:

$ sudo lshw -C display
  *-display               
       description: VGA compatible controller
       product: GF104 [GeForce GTX 460]
       vendor: nVidia Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:16 memory:f6000000-f7ffffff memory:e0000000-e7ffffff memory:ec000000-efffffff ioport:bf00(size=128) memory:e8000000-e807ffff