IPhoto library upgrade failed, one third of the photos lost, but the library works as normal. No corruption.

Question

Hello! I recently replaced my tragically crashed Macbook Pro 2008 with a newer model and transferred my volumous iphoto library of 20 000+ photos to my new machine. To be able to use my iphoto '08 library with Aperture I had to upgrade the library in the iphoto '11 version. I left the computer on during the day, and when I got back it seemed to work fine. I browsed my library in Aperture and could see all the thumbnails, but looking closer I noticed a small yellow warning triangle with an arrow in the corner of some pictures. Turns out all pictures from before ~2010 are lost! When I wiev the photos I see nothing but the infinite black of the data void.
Here's how I've tried to fix the problem:
1. Opening the iPhoto Library package in Finder. All the folders for the earlier dates are there, but they are empty. I notice no incorrect or impossible dating, which seemed to be a common problem among users who's libraries where corrupted during the upgrade process.
2. Rebuilding the iphoto library in iphoto. No effect.
3. Recovering the iphoto library from my Time Machine Backup. SInce my old hard drive was just 200 GB, I stored all pictures older than one year on my external hard drive (note that about half of those pictures were successfully imported/upgraded). Both the internal and the external hard drive where backed up using Time Machine on a NAS from Seagate (Black Armor 110, 3TB). I was able to access backed up files on my external drive through Time Machine on my old computer, but since it is now rendered unbootable I tried using Migration Assistant to let my new computer inherit the old backup. However, I could not find the backup of the external drive in Migration Assistant, just my old internal drive. When I tried to access the backup volume on my NAS through Finder it didn't show up (I could find it that way on my old computer).
4. Googling "iPhoto library upgrade failed", or "Inheriting Time Machine backup of external drive", and similarily desperately specific phrases - Nothing useful. Other people seems to have had problems with corrupt Libraries, but I'm not sure that's the case here.
My pictures must exist somewhere on my computer and in a backup on my NAS. I just can't find them! Do anyone have a clue to what may have gone wrong? I'm afraid the computer might have gone to sleep during the upgrade, because I didn't thinkabout adjusting the power saving settings before starting it. But since pictures 1-8000-something are missing, it doesn't seem to have worked properly during the whole beginning of the upgrade, not just during the middle. As I knew I had a backup of the library I didn't worry about upgrading the single functional copy. From now on I will think thrice before doing anything as serious as this.
I am eternally grateful for any answers that might help me recovering my photos!
//Teodor Nilson

Answer 1

  b) I split up my photo collection into two iphoto libraries. One for the new photos stored on my internal HD            and one for photos older than one year stored on my external HD
And exactly How did you Split up your iPhoto library?
c) I used Migration Assistant in an attempt to access the Time Machine backup of my old MBP from my new      MBP (by inheriting the backup). When I made my backups, I made sure Time Machine included the external      HD. But Migration Assistant could only find the backup of my Internal HD with the library of new photos!
And again
You should not use Migration assistant on an iPhoto library - it generally does not work
and
     d)   When signing in and mounting the NAS in Finder, I used to be able to see a Time Machine backup      folder/icon. Now I was unable to locate it.
I believe you are using your NAS for your Time Machine backup. If your Time Machine backup and/or your iPhoto library is on a NAS you will have problems - both need to be on Mac formatted volumes - the least troublsome is a volume formatted Mac OS extended (journaled)
http://support.apple.com/kb/HT1427?viewlocale=en_US&locale=en_US
Manually preparing a new disk for Time Machine
If you want to erase a disk before using it with Time Machine, follow these steps:
Open Disk Utility (located in the Utilities folder).
Connect the disk if it isn't already attached.
In the left side of the Disk Utility window, select the disk you want to use with Time Machine.
Optional: If you want to partition the disk, click the Partition tab and select a layout. Make sure "Mac OS Extended (Journaled)" is selected in the Format menu for the partition that will be used for backups. Click Apply.
Click the Erase tab.
Optional: If you want to securely erase the disk, click Security Options to configure, then click OK.
Click Erase.
After erasing, open Time Machine preferences in System Preferences and configure as described in the section above.
Are the iPhoto libraries kept on an external drive formated Mac OS extended (journaled)? Or are they on the NAS? - If you are using the NAS for iPhoto and/or Time Machine that is the source of your problems
LN