I noticed today that Time Machine was taking an awful long time to do a backup, but I didn't think much of it until an alert popped up that said it was 150GB short of space. There's no change I gone near 150GB of changes to anything today, since the last hourly backup. I looked at the Time Machine HD, and there is only one folder left inside the backup.backupdb/Mac Pro/ folder, and in Time Machine there is only 'Today' left in the time bar thing. So it seems months of valuable backups have just vanished for no good reason! Is there any way to find out what Time Machine is trying to backup, and why? And I assume there's not much hope of restoring my lost backups?