Iphoto not displaying some pictures

Question

For some reason, and this is recent, if I try to display a picture within iphoto, it just shows a doted square with an "!" in the middle. Preview brings the files up just fine. What gives?

Answer 1

Here's your problem then:
One additional item I need to add that may give you more information is that my wife and I use the same iphoto library with different user accounts in the imac. I have the library located on the users\shared folder and her user and mine have read/write access to it.
This form of Sharing is deprecated in 10.5 unless you're using iPhoto 09 (specifically v8.0.2) What you're having is a permissions issue caused by the ACL's used in Leopard. iPhoto cannot access the version of the Folder it needs.
You need to either:
1. Upgrade to iPhoto 09 (v8.0.2)
or
2. Change the system of Sharing you use:
What you mean by 'share'.
If you want the other user to be able to see the pics, but not add to, change or alter your library, then enable Sharing in your iPhoto (Preferences -> Sharing), leave iPhoto running and use Fast User Switching to open the other account. In that account, enable 'Look For Shared Libraries'. Your Library will appear in the other source pane.
Any user can drag a pic from the Shared Library to their own in the iPhoto Window.
Remember iPhoto must be running in both accounts for this to work.
If you want the other user to have the same access to the library as you: to be able to add, edit, organise, keyword etc. The problem here is that OS X works very hard to keep your data safe and secure from the other users. You're trying to beat what's built in to the system. So, to beat the system
Quit iPhoto in both accounts
Move the iPhoto Library Folder to an external HD set to ignore permissions. You could also use a Disk Image or even partition your Hard Disk.
In each account in turn: Hold down the option (or alt) key and launch iPhoto. From the resulting dialogue, select 'Choose Library' and navigate to the new library location. From that point on, this will be the default library location. Both accounts will have full access to the library, in fact, both accounts will 'own' it.
However, there is a catch with this system and it is a significant one. iPhoto is not a multi-user app., it does not have the code to negotiate two users simultaneously writing to the database, and trying will cause db corruption. So only one user at a time, and back up, back up back up.
Lastly: This method seems a little clunky at first, but works very well. Most importantly, it uses the System to do the job for you.
Create a new Account on your Mac, call it Media. Create an iPhoto Library there. (BTW: This will work for iTunes too.)
Enable Sharing on the Library:(Preferences -> Sharing), leave iPhoto running and use Fast User Switching to open the other accounts. In those accounts, enable 'Look For Shared Libraries'. The Library will appear in the other source pane.
This means that both users will be able to see the pics. If you want to use a pic then simply drag it from the shared Library to your own in the iPhoto Window. This means that each user can have their own edits.
If you want to add photos to the Library: Log into the Media account for that purpose.
To make it all seamless: Set your Mac to log into the Media Account automatically. Set iPhoto to launch on log-in. Then switch to your own account using Fast User Switching.
Net result: a Library that's permanently available to all users but also protected. Each user can have their own versions of the pics if they want.
No partitioning, no permissions issues. Uses no extra disk space. What's not to like?
Regards
TD