Better GCal Colorize Weekends Not Working

I love the better GCal Firefox extension but for some reason the "colorize weekends" option doesn't work. I've tried it for both weekends that start on Monday and Sunday and refreshed but neither seem to work. I'm running Mac OS X Leopard and the latest version of Firefox (3.0.7). Any ideas why this wouldn't be working or how I can fix this?

Thanks