As a Test:
Hold down the option (or alt) key and launch iPhoto. From the resulting menu select 'Create Library'
Import a few pics into this new, blank library. Is the Problem repeated there?
moved my iPhoto folder to Google Drive to back these up online.
iPhoto needs to have the Library sitting on disk formatted Mac OS Extended (Journaled). Users with the Library sitting on disks otherwise formatted regularly report issues including, but not limited to, importing, saving edits and sharing the photos. Are you sure your back up won't be corrupted?
I created a new blank library and imported some photos as suggested. I quit iPhoto and when I restarted it the photos were all still displaying. I then created some events but it would not save the name I gave them. I quit iPhoto, restarted and tried again. This time the names were retained. I then created some new events and again the name would not save. I quit iPhoto, restarted it and this time the names will not save.
In terms of where my library is stored it is still on my main drive where the original library was, just in a different folder.
So it looks like the problem is improved with a new blank library but not completely resolved. Does this provide any insight as to what the problem might ne?
Try this basic troubleshooting: make a temporary, backup copy (if you don't already have a backup copy) of the library and try the following:
1 - delete the iPhoto preference file, com.apple.iPhoto.plist, that resides in your
User/Home/Library/ Preferences folder.
2 - delete iPhoto's cache file, Cache.db, that is located in your
User/Home/Library/Caches/com.apple.iPhoto folder (Snow Leopard and Earlier).
or with Mt. Lion from the User/Library/Containers/com.apple.iPhoto/
3 - launch iPhoto and try again.
NOTE: If you're moved your library from its default location in your Home/Pictures folder you will have to point iPhoto to its new location when you next open iPhoto by holding down the Option key when launching iPhoto. You'll also have to reset the iPhoto's various preferences.
NOTE 2: In Lion and Mountain Lion the Library folder is now invisible. To make it permanently visible enter the following in the Terminal application window: chflags nohidden ~/Library and hit the Enter button - 10.7: Un-hide the User Library folder.
I deleted the preference file as per step 1.
I deleted the cache.db file from the location specified for Snow Leopard and earlier. I am on Mountain Lion but there is no folder for com.apple.iPhoto under Containers. Is this because the Mac came with Snow Leopard when I bought it?
I restarted iPhoto, tried to recover orphaned photos and there is still no sign of the events I created. The recent photos are definitely in the iPhoto package file.
Since iPhoto works as it should in the new account your current account is causing the problem. It could be a preference file other than iPhoto's that is interferring with iPhoto. Here's a way to determine if that's the case:
Trouble Shooting Preferences
NOTE: In Lion and Mountain Lion the Library folder is now invisible. To make it permanently visible enter the following in the Terminal application window: chflags nohidden ~/Library and hit the Enter button - 10.7: Un-hide the User Library folder.
1 - close all applications.
2 - open your Home/Library folder and Option-drag (copy) the Preferences folder to the Desktop.
3 - select the contents of your Home/Library/Preferences folder and drag them into the Trash bin in the Dock. You will be asked to provide your Admin password.
4 - reboot.
5 - run the application again and determine if the problems is fixed
6 - If the problem is fixed:
A - open the working Home/Library/Preferences folder.
B - Open the Preferences folder on the Desktop, select all of the contents and drag them into the working Home/Library/Preferences folder.
C - When the Copy window pops up check the "Apply to All" check box and then click on the Don't Replace or Skip button.
D - reboot.
7 - If the problem is NOT fixed, drag the contents of the Preference folder on the Desktop into the Home/Library/Preference folder and replace the entire contents that were created by clicking on Replace.
8 - reboot.
I followed your instructions but still no progress. I deleted the preferences folders, rebooted, ran iPhoto and rebuilt the library looking for orphans and these still do not appear.
I have had a look at the package contents and I noticed that iPhotoLock.data was created on 16 Nov 2009 which is when I got my Mac. iPhotoMain.db was created on 11 Dec 2012 and I have no photos dated since 8 Dec 2012 in my events. Does that provide any clues?