Windows resets resolution&refresh after reboot

I have a GigaByte ATI Radeon 9200SE (128MB) AGP8X graphics card in my Asus nForce2 A7N8X-X motherboard. I have the ATI Catalyst 4.2 drivers installed. My current resolutin is 800x600@100Hz

Now everytime I reboot the computer, Windows puts 640x480@60Hz. What’s going on here?