Is the letter O or 0 (zero).

If it's a 0 (zero), and the : character on your keyboard is typed with SHIFT down, then it may be that the second character is typed unshifted. You should try letting go of the shift key in between tying in : and )

You can also try to type something as uppercase only (holding down shift - do not use caps lock), and see if it types some characters unshifted on the alts.