i knew it along ago. i think nokia did it in purpose. the space button of course must be long and because of its length it is somehow not really easy to press. the space here has been seperated into to to make it easier.
i type alot and i never press right on the middle of the botton. it is on both sides when i use keyboard of N900. one of the button is used for @.
just try it yourself and you will see.. importantly i dont think we can do anything with it.