Permission issues between multiple users in iPhoto (on iMac)?

I never had an issue with permission for sharing iphoto among 3 users on my iMac until I got the latest version of iLife several months ago. Now, all users can see all existing photo's but when anyone adds new photo's from a camera, the others can't see them (they can see the thumbnail, but comes up with the nasty yellow triangle when trying to view full size).

Yes, I have all the "permission for sharing among all users" set (I've checked this, and as I said, never had issues before).

I have found a fix by holding down the Option and Command keys as I open iPhoto, then checking the bottom box to "Examine and repair iphoto permissions". This fixes all permissions for all users, by why do I have to monkey with that every time I add more pictures? Never had to do that before I had the newer version of iLife.

Why do I have to "repair" permissions every time I add new photo's???