BootCamp usually has some drivers it provides if you created the partition where Win7 Ultimate lives using the BootCamp Installer process. If you run Software Update on the Mac side do you get a newer version of the BootCamp software by any chance?
On the Win7 side there's also BootCamp/Software Updater that you can run. There's a System Tray icon that looks like a gray diamond. You could try that as well, to see if it can pulldown some newer hardware drivers too.