I have a PPC Mac Mini with the latest version of Leopard that I use to locally host all of my media files, backups, etc. Until this past week it's had no problem sharing multiple folders/HDDs with my other network computers and AppleTV 2. Suddenly, I can't connect to it with any devices, screen sharing doesn't work, but controlling remotely with Apple Remote Desktop does work. I've made no changes to the computer to cause this problem, I've reset the sharing settings multiple times, I've gone back to a functional date in Time Machine and grabbed a few of the sharing related .plist files (possibly not all of them) and replaced the current ones with them. Nothing. I'm stuck - any advice?