Comment 7 for bug 23816

I've got the same issue (i915 on a Samsung X20).
When trying to get hardware acceleration working, I first had the replacement i810 driver from
http://www.fairlite.demon.co.uk/intel.html together with the xorg.conf Option "ForceBIOS" "1280x1024=1400x1050".
That worked, but disabled hardware acceleration due to libGL complaining about something.
The screensavers were unaccelerated, but fit properly into the screen.

The cut-off screensavers came into play when I tried it the other way, with the standard driver
and the 855resolution tool setting the VBIOS values to mode 58 (1400x1050).
That way hardware acceleration is working, but the screensavers suffer from the described issues.

My xorg.conf is a completely standard one with i180 driver and no special options.