They should match assuming you have the soft proof set in PS using Paper White simulation which in CS3 is stuck 'on' in that dialog (not any more in CS4).
Then there's a difference in preview size.
Thanks Andrew -
Even with paper simulation on, and, albeit, a degree of squinting, I'm seeing a tangible difference. Oh well. A color management hell session awaits, it seems...
David
SOLVED: I discovered that somehow the colour settings in CS3 were incorrect: it had, somewhow, reverted to the North American preset, and strangely, to desaturate by 19%. I'd certainly never set that up. So I learned two things: one, desaturate in colour setup does not affect the match colors in Print preview, and two, don't do this stuff at 11pm when you've been up since 6am and spent all day in front of a computer....