xf86MapVidMem: Could not mmap framebuffer

Hi,

I have followed the instructions https://wiki.ubuntu.com/HardwareSupportComponentsVideoCardsPoulsbo/
I am using Maverick on a O2 Joggler, it has 512MB RAM.

Based on Intel's Poulsbo/US15W mobile chipset.
CPU: 1.3GHz Intel Z520 Single-Core, Hyper-threaded, Atom CPU
Chipset: Intel US15W (400/533MHz FSB)
Graphics: Intel GMA500

When trying to startx I get the error:
Fatal server error:
xf86MapVidMem: Could not mmap framebuffer (0x1f9dd010,0x800000) (Resource temporarily unavailable)

Kernel parameters: root=/dev/sda2 ro acpi=force mem=384mb

The interesting bit from the kernel.log:
kernel: [ 122.229465] Xorg:1331 conflicting memory types 1f9dd000-201de000 uncached-minus<->write-back
kernel: [ 122.229476] reserve_memtype failed 0x1f9dd000-0x201de000, track uncached-minus, req write-back

From Xorg.0.log

[ 122.220] (II) Module vgahw: vendor="X.Org Foundation"
[ 122.220] compiled for 1.9.0, module version = 0.1.0
[ 122.220] ABI class: X.Org Video Driver, version 8.0
[ 122.221] (II) PSB(0): Debug: MMIO virtual address is 0xb7728000
[ 122.221] (--) PSB(0): Mapped PCI MMIO at physical address 0xd0100000
 with size 512 kiB
[ 122.229]
Fatal server error:
[ 122.229] xf86MapVidMem: Could not mmap framebuffer (0x1f9dd010,0x800000) (Resource temporarily unavailable)

Help is greatly appreciated.
Thank you,
Shaun