Whilst browsing the Lubuntu Blog for installation issues, I came across a known bug in the keyboard layout for some languages (in particular, GB Eng) - reading the bug report suggests that this problem exists across all flavors of the Ubuntu 14.04 distribution.
If my previous suggestion on fixing your keyboard language doesn't work, there are a number of fixes in the bug report. As always, try the simple ones first & in this case, Branimir Butorac's post (26) put me on the right track for my Ubuntu installation on the DELL Inspiron 6400.
Open The settings Menu & select Language Support from the Personal settings. Under the Keyboard input method system, select none.
Reboot to check persistence.
Sources & References:
- Ubuntu Launchpad Bugs: IBus does not support certain keyboard layouts