Comment 4 for bug 748308

I'm having the same issue. Build my own Ubuntu livecd using live-helper and included the fglrx driver. When ubiquity is started the following error is generated:

cat /var/log/installer/dm

X.Org X Server 1.10.4
Release Date: 2011-08-19
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-29-server i686 Ubuntu
Current Operating System: Linux live 3.0.0-16-generic #28-Ubuntu SMP Fri Jan 27 17:50:54 UTC 2012 i686
Kernel command line: initrd=/casper/initrd.lz file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash -- BOOT_IMAGE=/casper/vmlinuz
Build Date: 19 October 2011 05:09:41AM
xorg-server 2:1.10.4-1ubuntu4.2 (For technical support please see http://www.ubuntu.com/support)
Current version of pixman: 0.22.2
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Thu Mar 1 12:46:53 2012
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) Failed to load /usr/lib/i386-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/linux/libfglrxdrm.so: libatiuki.so.1: cannot open shared object file: No such file or directory
(EE) LoadModule: Module fglrxdrm does not have a fglrxdrmModuleData data object.
(EE) Can't load FireGL DRM library (libfglrxdrm.so).
(EE) Failed to load module "ati" (module does not exist, 0)
(EE) Failed to load module "vesa" (module does not exist, 0)
(EE) Failed to load module "fbdev" (module does not exist, 0)
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:1:1) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:17:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:18:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:18:2) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:19:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:19:2) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:20:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:20:2) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:20:3) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:20:4) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:20:5) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:21:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:21:3) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:22:0) found
(WW) fglrx: No matching Device section for instance (BusID PCI:0@0:22:2) found
(EE) Failed to load /usr/lib/i386-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/linux/libfglrxdrm.so: libatiuki.so.1: cannot open shared object file: No such file or directory
(EE) LoadModule: Module fglrxdrm does not have a fglrxdrmModuleData data object.
(EE) fglrx: Failed to load module "fglrxdrm" (invalid module, 0)
(EE) fglrx(0): Failed to load DRM library
(EE) fglrx(0): PreInit failed
SetVBEMode failed
(EE) Screen(s) found, but none have a usable configuration.

Fatal server error:
no screens found