Kernel Oops - BUG: unable to handle kernel paging request at fa5a4ffc; EIP is at evergreen_cp_start+0x49/0xae0 [radeon]

I've radon blacklisted through a conf file in modprobe.d directory
Inside a X session I've modprobe radeon. No problem here
Then I've echoed OFF to /sys/kernel/debug/vgaswitcheroo/switch. No problem here
Radeon card was off according cat /sys/kernel/debug/vgaswitcheroo/switch and lspci | grep VGA (ff present for radeon). Also fan stopped a while after.
Then I've suspended. Ok here.
Resumed again with no problem.
Then I've echoed OFF to /sys/kernel/debug/vgaswitcheroo/switch. No problem here BUT
card seemed not being turned off. cat /sys/kernel/debug/vgaswitcheroo/switch showed the radeon as off, but
lspci | grep VGA doesn't showed the ff at the end.
So I tried to power ON the radeon card again (in order to turn it off then), and I've gotten the kernel "oops"

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-7-generic-pae 2.6.38-7.39
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic-pae 2.6.38
Uname: Linux 2.6.38-7-generic-pae i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Annotation: Your system might become unstable now and might need to be restarted.
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: avelo 1478 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xc4500000 irq 44'
   Mixer name : 'IDT 92HD81B1X5'
   Components : 'HDA:111d7605,103c1433,00100402'
   Controls : 14
   Simple ctrls : 9
Card1.Amixer.info:
 Card hw:1 'Generic'/'HD-Audio Generic at 0xc4420000 irq 45'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100200'
   Controls : 4
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Sun Mar 27 10:04:42 2011
Failure: oops
HibernationDevice: RESUME=UUID=46c85b58-0b5e-445a-96f7-b4c89b55c73d
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110318)
MachineType: Hewlett-Packard HP Pavilion dv3 Notebook PC
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic-pae root=UUID=3649ca80-c20a-4f33-b4d0-7d0cb1545cab ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-7-generic-pae N/A
 linux-backports-modules-2.6.38-7-generic-pae N/A
 linux-firmware 1.49
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Title: BUG: unable to handle kernel paging request at fa5a4ffc
UpgradeStatus: Upgraded to natty on 2011-03-24 (2 days ago)
dmi.bios.date: 02/14/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.26
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 1433
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 58.28
dmi.chassis.asset.tag: CNU02549TF
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.26:bd02/14/2011:svnHewlett-Packard:pnHPPaviliondv3NotebookPC:pvr0492100000202B10000020000:rvnHewlett-Packard:rn1433:rvr58.28:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.name: HP Pavilion dv3 Notebook PC
dmi.product.version: 0492100000202B10000020000
dmi.sys.vendor: Hewlett-Packard