This afternoon, my Address Book mysteriously emptied itself. Looking through ~/Library/Addresses/Address Book.addressbook, I saw that all my contacts appear to be there, but when I try to sync my iPod, iSync tells me that there are 670+ contacts to delete. I tried moving the iSync.vcf off my iPod and then importing it into Address Book, but the import process doesn't populate the window with my contacts.

I tried logging in as another user and successfully imported the iSync.vcf file. Then I tried exporting it, logging back in as me, and re-importing. Address Book hung.

I tried deleting ~/Library/Addresses/ and ~/Library/Preferences/com.apple.AddressBook.plist, and tried importing either the iSync.vcf file or the other, new file. In the case of the file from my iPod, it zipped through, but did not create a new ~/Library/Addresses folder or any new contacts. In the case of my imported-then-exported file, Address Book hung again. I'm stumped. I need this data on my effing Mac. What do I do? Discuss

P.S.: Perhaps it's worth noting that over the weekend, I suddenly became unable to save any files. Every attempt to save a file returned a Disk Full warning (3+ GB available on my disk). I rebooted, and the problem was solved, but all my Mozilla cookies, bookmarks, and stored passwords were gone, as were all my Mail.app preferences. Perhaps this is related?