I started with 12.10 and later I upgrated to 10.40.
I have also tested 12.04 32bit in the mean time (see comment #53)
I  think the kind of freezes were over all the time always the same. 
I am now running on Debian 7.1 which shows the same freeze with default kernel 3.2. 
So I updated yesterday to the kernel  from the  backports - version 3.10-0.bp0.2.

During my excursion to Debian I saw that there is a missing firmware (this was also logged under ubuntu but it did look to me that it was not a problem so I did not investigate into that. Debian complained about the missing firmeware when I try to install a kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/  , and forced me to uninstall it when I opened synaptic. 
So I was unable to install the kernels in a successful way. 

Now finally I succeeded with the backport version 3.10-0 by providing also the package firmware-iwlwifi_0.40_all.deb

The system log looks now (for me) cleaner. I see messages like this:


Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.763834] [drm] Initialized drm 1.1.0 20060810
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.768513] cfg80211: Calling CRDA to update world regulatory domain
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.777166] Intel(R) Wireless WiFi driver for Linux, in-tree:
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.777169] Copyright(c) 2003-2013 Intel Corporation
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.781881] [drm] Memory usable by graphics device = 2048M
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.784463] iwlwifi 0000:01:00.0: firmware: agent loaded iwlwifi-2030-6.ucode into memory
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.784661] iwlwifi 0000:01:00.0: loaded firmware version 18.168.6.1 op_mode iwldvm
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.802459] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.802461] [drm] Driver supports precise vblank timestamp query.
....
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.611346] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.611349] i915 0000:00:02.0: registered panic notifier
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.635952] acpi device:49: registered as cooling_device9
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.647893] ACPI: Video Device [GFX0] (multi-head: yes  rom: no  post: no)
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.648007] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A08:00/LNXVIDEO:00/input/input8
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.648275] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.671144] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input9
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.671265] input: HDA Intel PCH Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input10
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.671381] input: HDA Intel PCH Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input11
Sep 12 22:40:36 ralpus-ultrabook kernel: [    2.971332] Adding 10157052k swap on /dev/sda5.  Priority:-1 extents:1 across:10157052k SS


I think I never saw a message like this before:

Sep 12 22:40:36 ralpus-ultrabook kernel: [    1.781881] [drm] Memory usable by graphics device = 2048M

Also the messages like the next one are gone:

[52682.020393] CPU0: Package power limit notification (total events = 5746)


I hope this can help in any way.

So I am now waiting for the next freeze :-/