It is almost 2010 and printing is still far too complex. The Apple software, the various printer software versions and those of other supporting programs like Photoshop, Elements, etc. still do not play well with each other.
It is all too difficult to simply set the size you need (like in this post). Why is that hard? It shouldn't be and shouldn't require all sorts of nerdy work-arounds. Should the average computer user have to know about all that stuff? Ridiculous.
I have gone around in circles many times trying to size the output, get color that approximates the screen, and all that. The only thing that you can depend on is the Out of Ink, Buy More dialogues. I think they spent most of their money on that when they write the software..
Remember WYSIWYG? (buzzer sound). It seems like it takes 29 steps, some redundant, to print a stinking decent photo.
What is needed is a Printing Unification program that gives you one decent control so that you can actually print something nice easily, the first time, not matter what the printer or other programs.