Something is gone really wrong with fonts from Maverick to Natty

[Lorem]

I've always used this configuration for fonts:

font family: sans 9
Smoothing: subpixel
Hinting: full

And in Maverick i gave the following command to enable Firefox to follow the gnome-appearance-properties settings:

sudo rm /etc/fonts/conf.d/10-*

But with Natty, the fonts in Firefox are really strange (and ugly). In the attached screenshots take a look, specially, at the 'a,g,G,O' chars, and in general to the different style and size of the font.

Note that if i use 'slight' hinting some glitches come up, and the final result is worst than with 'full' hinting

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: xorg 1:7.6+4ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] È una directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 270.41.03 Sat Apr 9 00:06:19 PDT 2011
 GCC version: gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu3)
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,shift,place,mousepoll,grid,gnomecompat,regex,move,wall,imgpng,vpswitch,session,resize,unitymtgrabhandles,animation,expo,workarounds,ezoom,fade,scale,unityshell]
CompositorRunning: compiz
Date: Wed Apr 20 16:53:06 2011
DistUpgraded: Fresh install
DistroCodename: natty
DistroVariant: ubuntu
DkmsStatus:
 nvidia-current, 270.41.03, 2.6.38-8-generic, x86_64: installed
 virtualbox-ose, 4.0.4, 2.6.38-8-generic, x86_64: installed
GraphicsCard:
 nVidia Corporation GF106 [GeForce 450 GTS] [10de:0dc4] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: CardExpert Technology Device [10b0:0401]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta amd64 (20110413)
JockeyStatus: xorg:nvidia_current - Driver grafici accelerati nVidia (Proprietario, Abilitato, Non in uso)
MachineType: System manufacturer System Product Name
ProcEnviron:
 LANGUAGE=it_IT:en
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=b6c66ebc-9e9f-41a2-aff7-fe5ea49c2357 ro quiet splash vt.handoff=7
Renderer: Unknown
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
XorgConf:
 Section "Device"
  Identifier "Default Device"
  Option "NoLogo" "True"
 EndSection
dmi.bios.date: 02/18/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0704
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: P8H67-V
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0704:bd02/18/2011:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP8H67-V:rvrRevX.0x:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz 1:0.9.4+bzr20110415-0ubuntu2
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental 7.10.2-0ubuntu2
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu2
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[penalvch (penalvch)]

Lorem, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p xserver-xorg-video-nouveau REPLACE-WITH-BUG-NUMBER

Please note, given that the information from the prior release is already available, doing this on a release prior to the development one would not be helpful.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Launchpad Janitor (janitor)]

[Expired for xserver-xorg-video-nouveau (Ubuntu) because there has been no activity for 60 days.]