iPhoto '11 9.1.5 update broke 150GB library?

Okay, here's the problem I'm having in a nutshell:

A client has about 150GB of photos in iPhoto '11. Everything was working fine until Monday when we did some standard software updates which included OS X 10.6.8 v1.1, iPhoto 9.1.5 update, and others. On first launching iPhoto after the update (the system had restarted due to the 10.6.8 update) the library started to be upgraded and then the "Your photo library is either in use by another application or has become unreadable" message appeared. Running any combination of the repairs resulted in no progress (in fact, it stalled at "Recovered 75330 versions" for over two hours). The iPhoto Library is still the same size it should be, and everything about it seems normal.

Here's what I have tried:

1) iPhoto Library Manager is useless because the albumdata.xml file does not exist and iPhoto will not bring the library to the point of rebuilding that file. Albumdata.xml is also not backed up by Time Machine, so there's no way of using utilities that take advantage of that file.

2) Going back with Time Machine and restoring the library to its proper location results in an error after about 20-50GB

3) Manually looking through *computername*.sparsebundle on the Time Capsule and finding a version of the iPhoto Library before the upgrade occurred works, however once it is copied over and placed in the right spot and selected with iPhoto, the original message about it being unreadable or in use happens.

4) Changing permissions or fixing permissions with the built in selections in iPhoto changes nothing

My question to the community is - is this library permascrewed?

Does iPhoto 9.1.5 have some kind of inherent problem with very large iPhoto libraries?

Will it actually fix the library if I check the first two and last one of the check boxes in the iPhoto repair screen, if so how long will it take with a 150GB library?

My next attempt will be to install iPhoto '11 on another computer without updating all the way to 9.1.5 and I will see if it opens that way.

Basically, this client has so many folders and albums that it's not worth it to just import the raw picture files to a new library, even if separated by event. He used to use Aperture but that created backup issues so he switched to iPhoto.

Anyone have any suggestions? The system is a MacBook Pro 15" early 2011 if that makes any difference.