Sorry for the wordiness... Got a new Mini just after Thanksgiving to replace my aging iMac. I've been using TM on an external FW800 drive since the days of Leopard all the way up through 10.8.2 on the iMac and also using Time Machine Editor all that time to do TM backups only at 6AM and 6PM every day instead of every hour. It's worked flawlessly for years. Anyway, got the Mini (came with 10.8.1 installed on 1TB internal HDD about 300GB used) set up to do TM backups to a 2TB external HDD connected via FW800 using Time Machine Editor with the same 6AM/6PM schedule. This week I notice on the TM disk icon on my desktop it keeps saying 1.6TB free of 2TB every day. I'm thinking the space used should keep increasing every day, so I look at the TM volume and it shows 2 backups (6AM and 6PM) every day from 2 Dec (when I first fired up TM) until 14 Dec (last Friday) and a "Latest" folder with a backup in it....nothing stored for the 15th thru 18th. Yesterday when I look at TM in the menu bar it shows the last backup as 6AM on Dec 18th, which was correct - but where were the prior 4 days backups? So, last night I turned off Time Machine Editor and enabled Time Machine to do its normal "every hour" backup....and it promptly kicked off a backup. I wake up this morning and look at TM at about 5:30AM, and still the only backup folder on the disk prior to "Latest" is Dec 14th....but TM says the last backup was performed today at 5:08AM. If I actually call up Time Machine, there are no backups listed between latest and Dec 14th either. So my question is it seems like TM is performing backups on schedule as it should (I don't get any errors), but it's not saving them properly...the last backup performed is wiping out the one before it instead of that previous one being pushed into its own folder. Like I said, it worked fine for 12 days, and now this....any ideas?