I struggled recently with a bug on a desktop running Lucid. Whenever I would log in, I got a session set to 1024x768. I would go to the nvidia-settings, reset it to 1280x1024 and it would be fine. As I didn't have much time for it and logged in only once a week or so, I kept doing this for some time, but it ended up bugging me quite a bit. Then this morning, I found this bug report.
So if you're experiencing this bug, it's very easy to fix:
- Edit your ~/.config/monitors.xml
- Adapt it to your configuration (in my case, that's 1280x1024 and a rate of 60Hz).
- Log out and back in.