..for instance - what is a 'test user account'?
A test user account is a pristine account you maintain on your Mac to log into to see if an issue in your regular account remains an issue; whether or not an issue in your main account remains an issue in your test user account gives us an idea of where the root of your issue may lie.
(The following assumes that you're running Snow Leopard.) The easiest way for you to test is to navigate to /Applications/System Preferences > Accounts, make sure the padlock is unlocked, and activate your Guest Account. (I'm assuming you're not already using it, and I'll have to give you further instructions if you are.)
Log in to your Guest Account, and tell us if iPhoto exhibits the same behavior in it as it does in your regular account.
Please also feel free to ask about any other suggested troubleshooting steps you don't understand so we can maybe resolve your issue before New Years.
