After creating a xorg.conf I've got able (there was a nasty bug in confless mode: always overlaying the second display over the first instead of using the second physical screen) to set up a second display (a DSUB-attached classic 17-inch panel) with ARandR (under XUbuntu 11.10) on Intel GMA X4500MHD (a Dell E5500 laptop). But the maximum resolution appearing in it's menu (for this particular display) is 1024x768 while its native resolution is 1280x1024. How to fix this?
I use to switch between different external monitors (with different characteristics) and working without any some times, so I'd like to avoid any hardcoding. But, if it is hardly possible to make the thing detect supported resolutions correctly, I'd be glad to know how to add them manually (the way meant to work if the monitor is physically capable of a resolution specified, though not advertising it correctly).