It is generally wisest to only add the folders that you use on a
regular basis, and to avoid the infinite depth setting on a folder
unless you are sure that the folder contains no aliases to other
folders. For example, I have an alias to my home folder on my
desktop, and if I set QS to infinite depth on my desktop catalogue
entry, it would create an infinite loop as it kept finding my home
folder inside my desktop folder inside my home folder, which would
cause QS to keep indexing forever.