Thanks for the advice. I removed DirectX 8.0a using the DirectX Uninstaller, and reinstalled DirectX 7.0a. Then I installed the MS Force Feedback 2 and tested Rogue Squadron. Perfection! The game is now rock solid and works perfectly with the new stick.
Unfortunately, my old Logitech Wingman Extreme no longer works since I reverted back to 7.0a. The Game Controllers applet describes the Wingman Extreme as "not connected", when it definitely is connected. I double-checked the Creative Gameport Joystick device in the Device Manager, and there are no conflicts, so I don't know what the problem is. Oh well, no matter. I don't intend to use it anyway now that I have the Force Feedback 2 working correctly.
Thanks for your help.