iTunes Library Manager v5.2.1 is now posted. It fixes a problem some Tiger users were experiencing during the Rename routine.
On a technical note, I should point out that Tiger users will be unable to take advantage of the much faster load and save routines that Leopard users will experience. Under Leopard, rsync is used to back up files. However, the Tiger version of rsync can't be trusted to copy the resource forks of files correctly, so ditto is used instead.