I just posted this script in the script forum. It looks at each event on the selected timeline and find those that have multiple instances of the same fX. This happens to me quite a bit because I use the Paste Attributes feature, and when you paste attributes, it adds all fX to those already applied to the event. Perhaps I'm the only one that has been burned by this, but I got tired of finding my mistakes late in a project and then having to examine every $##!@ event to find the ones with multiple Color Correctors, or more than one application of the Levels fX.