There's probably more about the problem in this forum, seems like I saw something of the sort, just couldn't find "a very same case".
On an old Asus A3N laptop, I could start Karmic only with older kernel (2.6.28-18.) and rolled-back video driver (that well-known xserver-xorg-video-intel-2.4), otherwise the system froze on boot (Ubuntu logo -> black screen, only "brutal hard shutdown" possible)
After upgrading to Lucid beta1, everything worked OK (probably no changes were made to video driver/kernel used - or the changes made were "positive"). Same with beta2 and rc, respectively.
However, after the final release I decided to make a "brand-new" installation - ant that was a fatal mistake: the black screen freeze on boot is back.
Installing Karmic and network update doesn't help, either: when updating, Lucid wipes ver2.4 intel driver with no option to keep it.
In Lucid, a "driver rollback" is impossible: when I try to do it, an error message appears:
Well, of course I do have xserver-xorg-core installed (version 2:1.7.6-2 which looks "=>" than 2:126.96.36.1991) but...
The following packages have unmet dependencies:
xserver-xorg-video-intel-2.4: Depends: xserver-xorg-core (>= 2:188.8.131.521) but it is not going to be installed
E: Broken packages
Please does anybody know a working solution? Now it's possible to boot only in failsafe mode which is pretty "minimalistic" (even a dock or Avant window navigator don't look/work properly).
Would highly appreciate any good advice!