[Orgmode] Vertical split in Emacs 23

[Paul Mead]

Hi,

I've recently upgraded to Emacs 23, and I'm not at all impressed with
the vertical split that it seems to prefer when there's supposedly
enough buffer width to allow it - the Agenda gets squashed up and things
like the TODO quick selection menus look terrible.

Is there a way of changing this back to the old behaviour? Through
experimentation I've found that if I reduce the frame width sufficiently
it reverts to horizontal split but I like to work with emacs maximized
most often.

Thanks
Paul