Lisa,
Since you are now in desperation mode, I'll throw in my 2 cents (but allow for depreciation).
I found CS3 much slower than CS2 when I first installed it, and I had lots of problems with slow file loading and saving (I usually don't print from inside CS, so I don't know if printing was affected). Among other fixes, I tried upping (in preferences) the amount of ram for Photoshop, but things seemed to get even worse. Then I read somewhere that plugins generally use memory that isn't part of Photoshop's allotment, so I tried lowering the Photoshop memory to the minimum recommended (low end of what PS calls the "ideal range"), and indeed things sped up by a good bit.
I have done one other thing which has helped. For my XP Pro desktop I installed a utility called "EBoostr" which uses fast USB thumbdrives as a general cache. This seems to have made a significant difference.
I believe that Vista has such a feature built in, called "Vboost", I think. If you haven't done so, I suggest getting a fast thumbdrive or two and engaging Vboost.
I hope this helps. Do let us know what you eventually figure out.
-Eric
P.S. The behavior I had when CS3 was running slow sounds very much like your printer experience, but with saving or loading of files. When I saved a file in CS3, nothing would happen for sometimes 30 seconds or more, as if the hard drive had gone to sleep (impossible). By clicking on various parts of the CS3 window until I got a "CS3 not responding" message, or even trying to see what was happening in Task Manager, it would eventually wake up and save the file (very slowly).
What I believe was happening was a lot of file thrashing as parts of Windows' own file handling processes were being swapped in and out of memory because there was not enough memory left outside of Photoshop to do the simplest routines. The same might be happening with your printing.