Keyboard input of special case characters - on by default, please

Hi,

A have a problem that has only recently just started to happen. My
description might be a bit long winded, so please bear with me.

It seems that special case character input has somehow been turned on as
default, and I cannot find a way to turn it off. For example if I want to
type a ' symbol, it does not immediately appear. I have to hit the key twice,
in which case I will see 2 of the symbols, i.e. ''.

If I enter the following keys ' c in order, I get the ç character instead of
'c as I expect.

I have looked at the IME configuration (I only have 1 keyboard type
installed and no other languages). It only started recently, so maybe
something I have installed is causing this behaviour? Please help, its
frustrating the life out of me.

Thanks in advance