X won't start after kernel compile

[Bruno Buys <brunobuys@gmail.com>]

I managed to compile a new 2.6.12 kernel using this howto: 
http://www.debian-administration.org/articles/202.
The kernel boots ok and I have a prompt. But X won't start, with error 
'no core pointer' or something like that.
I already tried to dpkg-reconfigure xserver-xfree86, but the same error 
goes for every mouse option in there.
When configuring the new kernel, I tried to be economic, and removed 
lots of things that were enabled. Maybe I removed support for the 
device. The problem is, I'm having a hard time figuring which one is.
Here's the relevant part of .config:

(by the way, I have a ps2 mouse).

# Userland interfaces
#
CONFIG_INPUT_MOUSEDEV=m
# CONFIG_INPUT_MOUSEDEV_PSAUX is not set
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
# CONFIG_INPUT_JOYDEV is not set
# CONFIG_INPUT_TSDEV is not set
CONFIG_INPUT_EVDEV=m
CONFIG_INPUT_EVBUG=m

#
# Input Device Drivers
#
CONFIG_INPUT_KEYBOARD=y
CONFIG_KEYBOARD_ATKBD=y
# CONFIG_KEYBOARD_SUNKBD is not set
# CONFIG_KEYBOARD_LKKBD is not set
# CONFIG_KEYBOARD_XTKBD is not set
# CONFIG_KEYBOARD_NEWTON is not set
CONFIG_INPUT_MOUSE=y
CONFIG_MOUSE_PS2=m
CONFIG_MOUSE_SERIAL=m
CONFIG_MOUSE_VSXXXAA=m
CONFIG_INPUT_JOYSTICK=y
CONFIG_JOYSTICK_ANALOG=m
CONFIG_JOYSTICK_A3D=m
CONFIG_JOYSTICK_ADI=m
CONFIG_JOYSTICK_COBRA=m
CONFIG_JOYSTICK_GF2K=m
CONFIG_JOYSTICK_GRIP=m
CONFIG_JOYSTICK_GRIP_MP=m
CONFIG_JOYSTICK_GUILLEMOT=m
CONFIG_JOYSTICK_INTERACT=m
CONFIG_JOYSTICK_SIDEWINDER=m
CONFIG_JOYSTICK_TMDC=m
CONFIG_JOYSTICK_IFORCE=m
CONFIG_JOYSTICK_IFORCE_USB=y
CONFIG_JOYSTICK_IFORCE_232=y
CONFIG_JOYSTICK_WARRIOR=m
CONFIG_JOYSTICK_MAGELLAN=m
CONFIG_JOYSTICK_SPACEORB=m
CONFIG_JOYSTICK_SPACEBALL=m
CONFIG_JOYSTICK_STINGER=m
# CONFIG_JOYSTICK_TWIDJOY is not set
# CONFIG_JOYSTICK_JOYDUMP is not set
CONFIG_INPUT_TOUCHSCREEN=y
CONFIG_TOUCHSCREEN_GUNZE=m
# CONFIG_TOUCHSCREEN_ELO is not set
# CONFIG_TOUCHSCREEN_MTOUCH is not set
# CONFIG_TOUCHSCREEN_MK712 is not set
CONFIG_INPUT_MISC=y
CONFIG_INPUT_PCSPKR=m
CONFIG_INPUT_UINPUT=m

I'm using debian sarge. The 2.6.12-5 package was linux-source from 
debian unstable.

thanks!