Widescreen Change?

Hey all,
I have a small problem with my Dell Inspiron 8600, and more precisely with Windows handling the 1920x1200 resolution it's WUXGA screen has. I frequently reinstall Windows XP Pro (using the OEM CD), but everytime I do, the following happens:

I reinstall Windows, and when the laptop boots into Windows, the screen resolution is that of WXGA. Once the ATi 9600 drivers are installed (and I reboot), the resolution is fine. The problem is, that once I go into "Display Properties" to change something as trivial as the wallpaper or screensaver, my resolution and Windows animations change ever so slightly. The taskbar gets slightly larger, the system tray's 'balloon tips' are around twice as large, and the 'welcome' message is around 3 times as large.

Does anyone know why this happens? I get given the option to install larger fonts for my high resolution (via Dell's bundled driver disc), but I never install them, nor does it do it automatically.

Thanks for any help you guys can give,
Xcelsion!

(Btw, I'm new to the forum, so hi!)