I frequently speak to groups and I always use my Ubuntu laptop. Sometimes I have to adjust the settings to get the projector to recognize my PC feed. I recently upgraded to Ubuntu 12.04 and was unprepared for the problems I encountered.
I arrived at the New York City Google Developer's Group to talk about Go version 1.0, plugged in my laptop and the signal was automatically recognized, but the the workspace on both the aptop and the projector was suddenly split in half vertically. I tried modifying all the settings under display, but nothing helped. Since I only had 15 minutes until I had to speak, I ended up moving the browser with my presentation slides between two workspaces. This meant that it displayed correctly on the projector screen but was half off the screen of my laptop.
It worked well enough, and thankfully, I only had slides for this presentation and not code examples.
I had another talk the next week, so I worked through the workspace and display options and found that you need to reconfigure the default 4x2 workspace configuration. I used compiz, went to General Settings, chose the Desktop Size tab, and set:
Horizontal Virtual Size = 1
Vertical Virtual Size = 1
Number of Desktops = 1
and then everything lined up correctly on both the laptop and the projector.
Since I had numerous code examples and command line statements to execute in several terminals, I opened a tmux session.
It all worked out, but I felt like I had gone backward several versions of Ubuntu. This did not occur in the previous two releases, so I wonder if this has affected anyone else. I would like to know if it is specific to my Lenovo or if something radically changed in 12.04.
Let me know if you have had similar problems.