There was a whole other discussion of this issue in another thread in this Forum - I don't have the link on hand, but if you do a search you'll find it. There was much back and forth between Jeff Schewe, me and some others. The up-shot is that what's there is not a "bug" - it was all intentional, and some of the problem - the centering issue in particular, occurs because of design requirements for Windows Vista, different from XP.
While all that is no doubt valid, they didn't convince me it isn't a mess regardless. Nor did they convince "Jani" who observed very astutely that the print interface should have been designed to be configurable. The logic behind this suggestion is that the useability problems in CS3 differ depending on which version of the Epson driver you use and which OS you use. Therefore as long as many people are still using several Epson driver versions and either XP or Vista, it would help to have several configurations of the print interface. For my workflow, I aolved it all by keeping CS2 installed and I print from CS2 with Windows XP and Epson driver version 5.51. All works like a charm. But that's my solution for my set-up. It will differ for others with different combinations of hardware and software. Can drive one crazy.
I had read all of that other thread well before daring to upgrade to CS3. From the thread I was expecting to have to re-select my Epson for each new document I wanted to print, and I was willing to do so since that was the way God had designed Mac software.
Inconvenient, I thought, but no big deal, just a nuisance having to select the right printer for each and every new document. And as for the margins, I do most of my PS printing from either ImagePrint or QTR, so I wasn't worried there either. Plus, I have Qimage for emergencies, and I have kept my CS2 just in case I needed it (I am always skeptical of any new version of any software).
But I don't think even Jeff would claim that it was Adobe's intention to display the incorrect printer in the printer box (look closely at my screen shot: the selected printer in the rear window is my Epson, but the actual printer chosen in the smaller window (upper left corner) is my default HP.) (This is a straight screen shot, not a couple of images combined in PS.)
Even this bug --- and it is a bug, and apparently Adobe's rather than Epson's, since it is in Adobe's printer selection box --- isn't a killer, since there is a work-around: Select any different printer, and then select the Epson (or whatever one you want), and then the chosen printer really is the one that CS3 is looking at.
So, in spite of all of Jeff's protestations, I still say that printing in CS3 doesn't work quite right, at least in Windows XP, but the flaw is pretty minor. I certainly agree that it would be nice if Epson and Micro$oft got their acts together and made it possible for Adobe to allow centered printing.