compiz crashed with SIGSEGV in geis_configuration_get_value()

I got this bug when trying to install Ubuntu on my Macbook Air 4,2 using the instructions from here:
https://help.ubuntu.com/community/MacBookAir4-2

After using the fix-i915.sh script, I rebooted. The login screen appeared normally at full resolution. After I logged in only the desktop background and mouse appeared (mouse was movable with the trackpad). Then, after about 60 seconds, I got an error report that Compiz crashed (this report). Then about 5 seconds later, I got an error report that 2d-Unity had crashed (which sent me to Bug #850893 after I clicked submit report).

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.22.0-0ubuntu3
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
ApportVersion: 1.23-0ubuntu2
Architecture: amd64
CrashCounter: 1
Date: Fri Oct 7 08:39:13 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta amd64 (20110921.2)
ProcCmdline: compiz
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f2a86effd30 <geis_configuration_get_value+32>: mov (%rdi),%rdi
 PC (0x7f2a86effd30) ok
 source "(%rdi)" (0x00000000) not located in a known VMA region (needed readable region)!
 destination "%rdi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 geis_configuration_get_value () from /usr/lib/libutouch-geis.so.1
 GeisAdapter::Run() () from /usr/lib/compiz/libunityshell.so
 UnityScreen::UnityScreen(CompScreen*) () from /usr/lib/compiz/libunityshell.so
 PluginClassHandler<UnityScreen, CompScreen, 0>::get(CompScreen*) () from /usr/lib/compiz/libunityshell.so
 CompPlugin::VTableForScreenAndWindow<UnityScreen, UnityWindow>::initScreen(CompScreen*) () from /usr/lib/compiz/libunityshell.so
Title: compiz crashed with SIGSEGV in geis_configuration_get_value()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare