Comment 10 for bug 406651

WORKAROUND FOUND:

On a FRESH install of 2.6.28-11, I installed xserver-xorg-video-psb as documented and rebooted. This gave me the same "Failed to load kernel module "psb." This driver currently needs DRM to operate." errors as mentioned above.

As suggested by hardyrulz, I continued with low-res graphics, then did:

sudo apt-get install psb-kernel-source
sudo shutdown -r now

which TOTALLY worked! Yay! I had 1366x768 on my Aspire 751h!

But... my elation was short-lived. After using Update Manager to update EVERYTHING, I rebooted into 2.6.28-14 and got the same incompatibility errors as before.

pjman suggested a reinstall, which I attempted with:

sudo-apt install --reinstall psb-kernel-source

Which CRASHED my session. So the lesson here is DO NOT SIMPLY "REINSTALL." Don't feel bad, though, pjman. I would have totally tried that without your suggestion anyway. :)

So I rebooted and did:

sudo-apt remove psb-kernel-source

sudo apt-get install psb-kernel-source

sudo reboot

Awwww, yeah. I'm back at 1366x768, baby!

So it would seem that any time the Jaunty version changes, a "remove" and "install" of psb-kernel-source (and NOT a --reinstall) will do the trick!