I am having problems with my m4600 supporting dual monitors.
I have a ATI Radeon HD 6700M (from lspci) and have installed the ATI proprietary drivers for that model and followed the instructions found here.
The resolution is fine, however, when I first boot, the resolution is mirrored across both of my 1280x1024 monitors (computer is docked). When I attempt to change it to span my desktop using (as root) amdcccle, it logs me off and I have to log in again. I log in and the mirrored setup is the default again. If I try to uncheck the mirrored monitors using the Ubuntu display manager (default display application), it will log me off as well.
I had this working before the .xsession-errors file filled up my HDD and I was forced to shutdown. I reinstalled the ATI drivers like I said above, but cannot get this to work. I love Ubuntu, just not on Dells :).
Anyone have any solutions or advice on some next steps?