One computer can't see any other iPhoto shared libraries

Question

My Powerbook can't see any other computer's shared iPhoto libraries. However, all my other computers can see its iPhoto library.
All computers are running the same version of iPhoto.
I posted this in the iPhoto forum, but I'm reasonably sure this is a networking problem. Why? If I create another user on my Powerbook, it can see all the other shared libraries. So, the problem exists on only one account on one computer. I think there is a corrupt system setting in that account's ~/Library/ somewhere. Any suggestion which file it is? I've already dragged out likely culprits to no avail.
I have no problem sharing iTunes libraries; that works fine. So do file transfers to and from.
Here's what else I've done:
Verified iPhoto Preferences is set to "Look for shared photos" and "Share my photos" (obviously).
Tried requiring a password, and not requiring a password
Verified System Preferences > Sharing > Firewall has "iPhoto Bonjour Sharing" checked.
Deleted ~/Library/Preferences/com.apple.iPhoto.plist
Deleted ~/Library/Preferences/com.apple.systempreferences.plist
Deleted ~/Library/Preferences/com.apple.iApps.plist
Deleted ~/Library/Preferences/com.apple.digihub.plist
Turned off Little Snitch
Quit / restarted iPhoto a few times
Logged in / out, rebooted a few times
Researched iPhoto Help
Researched the discussion boards
Repaired permissions on both (as you can see, I'm resorting to voodoo tactics)
Dragged my iPhoto Library out of ~/Pictures and created a brand new empty library (more voodoo)
Googled the problem
Posted this topic
That's all I can think of to do.
So... what haven't I done?

Answer 1

If iPhoto works for one user on a computer, it ought to work for all users. So the program itself can't possibly be a problem. Right?
Apparently not. I deleted iPhoto, and reinstalled it. That fixed the problem for the one recalcitrant account.
The problem with voodoo is that sometimes, it works.