Lenovo Care key (XF86Launch1) stopped working with udev 164-2

Binary package hint: udev

After upgrading my natty laptop (Lenovo 3000 0768-AJU) to udev 164-2 and rebooting, the Lenovo Care key no longer sends XF86Launch1 like it used to. Instead it just logs these lines in dmesg:

atkbd serio0: Unknown key pressed (translated set 2, code 0xb4 on isa0060/serio0).
atkbd serio0: Use 'setkeycodes e034 <keycode>' to make it known.
atkbd serio0: Unknown key released (translated set 2, code 0xb4 on isa0060/serio0).
atkbd serio0: Use 'setkeycodes e034 <keycode>' to make it known.

Downgrading to 164-1 and rebooting restores the XF86Launch1 functionality to normal. But the problem reappears if I rebuild 164-1 from source, so perhaps something changed in one of the build dependencies.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: udev 164-2
ProcVersionSignature: Ubuntu 2.6.37-2.10-generic 2.6.37-rc1
Uname: Linux 2.6.37-2-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Thu Nov 11 05:16:25 2010
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release Candidate amd64 (20091020.3)
MachineType: LENOVO 0768AJU
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.37-2-generic root=/dev/mapper/btree-ubuntu ro i8042.reset cgroup_disable=memory apparmor=0 quiet splash
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: udev
dmi.bios.date: 06/04/07
dmi.bios.vendor: LENOVO
dmi.bios.version: 61ET37WW
dmi.board.name: CAPELL VALLEY(NAPA) CRB
dmi.board.vendor: LENOVO
dmi.board.version: Not Applicable
dmi.chassis.type: 10
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnLENOVO:bvr61ET37WW:bd06/04/07:svnLENOVO:pn0768AJU:pvr3000N100:rvnLENOVO:rnCAPELLVALLEY(NAPA)CRB:rvrNotApplicable:cvnNoEnclosure:ct10:cvrN/A:
dmi.product.name: 0768AJU
dmi.product.version: 3000 N100
dmi.sys.vendor: LENOVO