I have replaced Windows XP with Ubuntu 12.04 on my 2006 Sony Vaio (model PCG-7L1M VGN-FS485B, 1.73 GHz CPU, RAM upgraded to 2GB). It went OK and I was happy until:
Firefox needed to open a new window rather than a new tab every time I opened a link.
It developed a problem with upper and lower case so that it looked like the Caps Lock was stuck on, but actually it's intermittent. For example pressing “A” and holding it down would give something like: AaaAAAAAAAaaaaaAAAAaaaaaaaaaAaaaaa”. Same sort of thing with Caps Lock on. With numerals I can only get !"£$%^&*() etc. Holding down Shift gives just capitals. Now that had never happened with XP which was running well before I changed, so I do not think it is a hardware problem. The problem also sometimes corrects itself after a reboot. Using an external keyboard does the same thing.
Any ideas? Maybe I need to install a driver for the keyboard?