Problems w/ running CS3 on Vista

Hello. I've noticed that most of the threads in this forum deal with how to use the functions of Photoshop. My post is in regards to the performance of CS3 on my new computer. I hope this post isn't out of place on this forum. If so, then I apologize. Anyway, here goes....

I've got a project going with a church to create artwork that will be printed on vinyl wallpaper. So the artwork has to be done large and in high resolutions to insure its sharp when printed out that large. So my files are huge, and my old computer, a Pentium 3 system, couldn't handle it all. Untill I could get a new computer, my mom let me borrow her notebook (XP, Pentium 4, 2gig memory) to do the work on. I installed CS3 and my Wacom Intuos3 pen tablet on it, and besides the fact that it took my files 5 to 10 minutes to open, it worked well. I bought my new computer through ibuypower.com in October. Its a 3ghz Core 2 Duo, 4 gig of memory, Geforce 8800GTX system running Vista. After I installed CS3 and my pen tablet things seemed to be good at first. My files open much faster on it, no more than a few minutes now. But once I got around to creating new work on the computer, I noticed that my pen tablet was not as responsive as it was on the notebook. It works fine about 50% of the time, but the other half the time its really laggy. I'll start drawing, and the new line will stop rendering untill I stop drawing, and then it catches up. As you might guess, drawing blind like that is no good and I usually have to redo it untill it starts running the way it should. Now initially I thought I may not have the current Vista drivers for my pen tablet, but that wasn't the case. Then I started doing some work that didn't require the pen tablet, and I noticed that I have the same problem with the mouse. So the problem isn't the pen tablet at all. Its got to be how CS3 runs under Vista. It was running fine under XP on my moms Pentium 4 notebook, but not good on my superior new computer. Has anyone else here had similar problems? I've heard that Vista is a memory hog, so what are my options? I've considered dual booting, or even just going back to XP, but I'd rather not do anything that drastic untill I know I have no other options. Any help will be appreciated.

What image size are you working in? i have cs3 running on vista 64 and seems ok.

My image sizes have been roughly 8" x 22" at 1200dpi (just about as big as Photoshop would let me go). I'm running 32 bit Vista at the moment. I considered getting the 64 bit version, but after doing quite a bit of research decided against it for time being because I didn't want to run into any compatibility issues with any of my software or hardware devices. I do expect to get a performance gain once I do make the jump to 64 bit, as I should get full use of my 4G of memory. Maybe it was a mistake to play it safe. I don't know.