I hacked together a screen saver real quick yesterday and at first couldn't figure out why it wouldn't load settings from the .NET .config file. Well, it turns out that Vista was loading the screen saver using the old 8 character file name. "MyScreenSaver.scr" was turning into "MyScre~1.scr" and thus it couldn't find the .config file. Renaming to a shorter name was the quick fix.