the startup items in the "login" preferences are for programs that start on login to the computer...items in your startup folder int he library start up when the computer is turned on for appz like SETI@HOME...therefore, it is ok to delete items from this folder as long as you aren't planning on running the programs listed in there...eg. To run SETI when you login, when the computer is staring up, in the progress it will say "starting seti screensaver" or something. If it doesn't do this, you won't be able to run SETI when you login, hence the need for a restart after installing the SETI package