Comment 198 for bug 668415

@Robin J. Rogge
"And since i am running the 64bit version of Ubuntu, i actually have only 2 choices: live with this situation until it gets properly fixed or use XFCE."

I'm not sure what you're thinking, but in addition to ubuntu-desktop (Unity and Unity 2D), and xubuntu-desktop (Xfce4), gnome-shell (GNOME 3 with the GNOME Shell instead of Unity), gnome-fallback (GNOME 3 Fallback, which looks like the old GNOME 2 interface), lubuntu-desktop (LXDE), and kubuntu-desktop (KDE4 Plasma) all work on both the 64-bit and 32-bit versions of Ubuntu. There are no graphical interfaces packaged for Ubuntu that work just for one or the other architecture.

You might be thinking about there used to be only a 32-bit version of the Lubuntu desktop install CD. Well, (a) there are both 32-bit and 64-bit Lubuntu live CD's now, as of Lubuntu 11.10 (see https://wiki.ubuntu.com/Lubuntu), and (b) it has always been possible (and pretty easy) to install a 64-bit Lubuntu system by installing a minimal command-line only system (either from the alternate install CD or the minimal install CD, see https://help.ubuntu.com/community/Lubuntu/Documentation/AlternateInstall and https://help.ubuntu.com/community/Lubuntu/Documentation/MinimalInstall) and then installing the lubuntu-desktop package. And anyway, if you already have Ubuntu installed, you don't have to reinstall to get a new interface--just install one (or more) of the packages listed above.

If you decide you want to continue using Unity / Unity 2D, then you might consider setting the launcher to *never* hide. Then you'd have less usable screen space, but at least the launcher wouldn't be popping out at you when you don't want it to.