I've just installed Ubuntu 12.04 (64 bit). I hate unity, so I use gnome-session-fallback. Everything works fine (OK, not as well as it worked in gnome2...) but if I open a new window, it always appears in the top-left corner corner and its menu bar is behind my top menu bar (with application menu, places, etc.).
How can I fix it? It annoys me a lot. Please help!
If your video card supports 3D Accelleration, you might consider using the compiz window placement plugin.
Install compizconfig-settings-manager:
compizconfig-settings-manager
Hit Alt+F2 and type
compiz --replace
If you want to change the way the windows are placed on your desktop, start the compizconfig-settings-manager:
Hit Alt+F2 and type
ccsm
Find the "Place Windows" plugin, it will have an option called "Placement Mode", you can choose the one that you like best there.