Meanwhile I made a clean install of 12.04 and I'm still having this problem. Also I can say that it isn't the compiz-plugins-extra package as I didn't install it. So I guess it's something wrong with compiz in general (window placement/recovery as I said before).
Both of my laptops are Lenovo machines with onboard Intel graphics, maybe that helps.
Meanwhile I made a clean install of 12.04 and I'm still having this problem. Also I can say that it isn't the compiz- plugins- extra package as I didn't install it. So I guess it's something wrong with compiz in general (window placement/recovery as I said before).
Both of my laptops are Lenovo machines with onboard Intel graphics, maybe that helps.