Slow ffxml file - do they get corrupted

Do these files ever get corrupted or perhaps do entries remain from old components? I am working on a big filter and have begun optimizing. There is a noticeable lag every so often and when I leave the editor when FF becomes unresponsive. I also manually moved some of my old versions of this filter to an archive folder - not sure if there is some index that needs to be updated? It is a hefty file compared to others at 113k so not sure but other filters don't freeze like this one, and this didn't do it before I started optimizing (though it did render slower before).