Comment 0 for bug 907381

A fresh install of Ubuntu 11.10 on a Dell Vostro 3550 with all updates (OSS only - no proprietary drivers).

When connecting the laptop to an external monitor to extend my desktop the display settings are unstable. I choose to enable both the laptop panel, and the external monitor setting appropriate resolutions and apply settings. Sometimes the chosen settings do not "take". If they do apply, and I confirm that I want to keep the settings, at random intervals the display settings are auto-changed by the system. This may include:
- Resetting to "mirrored" displays at 1024x768
- Resetting to a single display on the laptop panel
- Resetting to a single display on the external monitor
- Some other weird combination.

E.g. When using my computer in a time range of 10 minutes i could get through 5 different dispositions and resolutions. It could be both display working fine, then only one but with wrong resolution, then the two again but with mirror, then just the second, and so on..

Some debug information below - happy to collect more if it's helpful.

$ sudo lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: ATI Technologies Inc NI Whistler [AMD Radeon HD 6600M Series]

$ sudo lshw -C video
*-display
description: VGA compatible controller
product: NI Whistler [AMD Radeon HD 6600M Series]
vendor: ATI Technologies Inc
physical id: 0
bus info: pci@0000:01:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:52 memory:e0000000-efffffff memory:f7b20000-f7b3ffff ioport:e000(size=256) memory:f7b00000-f7b1ffff
*-display
description: VGA compatible controller
product: 2nd Generation Core Processor Family Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 09
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:50 memory:f6400000-f67fffff memory:d0000000-dfffffff ioport:f000(size=64)