Comment 2 for bug 879971

I'm not able to reproduce this behavior on Precise with Ubuntu on an Intel gfx laptop in a docking station. I tried both with a single monitor and with an external monitor. Single-clicking to select the workspace always worked, and doubleclicking seemed to work as well.

I did notice some wonky screen painting problem but that's a separate bug, which I'll file subsequently.

Would you mind testing to see if the problem also is resolved in your case in Precise? If you don't want to install Ubuntu Precise, it should be sufficient to boot a Live USB session, configure the monitors, and see if it is working properly now. You can get the current Live USB desktop image at http://cdimage.ubuntu.com/daily-live/current/ and create a USB boot drive using usb-creator.