Photoshop :: CS4 Poor Dialog Window Performance With...

I am running dual 30 inch monitors each one at 2560x1600 resolution, on windows xp sp3 on an nvidia quadro FX 3700M (dell precision M6400 laptop) If I use CS4 from the single laptop screen, everything is fine. However, whenever Im on the huge dual screen desktop any dialog box activity has a very poor performance. For example, I select File>New and the dialog window takes some two to three seconds to draw on the screen... it might not seem like a big problem but it is very very annoying since I am used to the snappy response of the user interface from years of PS use. It really affects my workflow since I work with many files at the same time. Also, the bigger the dialog window the slower it takes to appear. If I select File > Save for Web and Devices, that dialog window will take up to five seconds to appear on the screen. The problem seems to get worse the longer the OS has been working, ie. if the PC is freshly booted the problem seems a bit lighter. So it might be related to video card memory or something. Here's what I have tried so far to solve this:Since what I'm using is a laptop, the driver choices are limited, however I've been able to force install the 181.20 version of the nvidia driver, but it made no difference. All the official driver versions (176 series) from Dell also have the problem.The problem doesn't seem related to Photoshop's use of the GPU as the problem remains while the GPU acceleration disabled.This problem is also present in PS CS3 as well as CS2 CS1 and version 7 which are all I am able to test.I was able to reproduce this problem on a desktop computer with the same setup on an nvidia quadro FX 5500 card. The dialog box window performance is really terrible.I did not notice this problem in any other application that spans the two screens, even high end 3d ones. Ok well it seems from my testing that Photoshop is simply bogged down by having such a huge desktop area to work with.